Influence of Stock on Scion, and Scion on Stock

Burrill: The Reciprocal Influences of Stock and Cion (1898)

Nikolai: Increasing Apple Cultivar Hardiness to -40°F. Pomona 25(4) (Fall 1994)
The late Percy Wright, a horticulturalist of some note in Prairie Canada, once related a very interesting story of hardiness with regards to peach trees in British Columbia's Okanagan valley. His uncle moved from Saskatchewan had moved west to the Okanagan and for sentimental reasons had grafted some ultra hardy Saskatchewan plums onto a few branches of the peach trees in his orchard. A harsh test winter arrived after a few years which decimated not only the peach crop, but also the trees themselves. Most were killed outright or at the least severely injured. However the peach trees with ultra hardy Saskatchewan plums grafted in the branches had no winter damage whatsoever! Percy Wright theorized that the hardy plum grafts had caused the peach trees to go dormant earlier, and thus not be harmed by the severe cold, which occurred early in the winter that particular year. If you have hardiness problems with peach trees in your area, try it. Perhaps this is what is required to give your trees that extra bit of hardiness.

Soviet Plant Physiology pp. 38-45 (1958)
1. The morphological and physiological nature of various parts of the crown differ. This qualitative difference materially influences grafts. Water conditions in the leaves of top level grafts are more stringent and the grafts, just as the top levels of the mentor crown, form more xeromorphic leaves.
2. As compared to graminaceous plants the more xeromorphic organization of the top level leaves does not lead to an increase in the intensity of transpiration; on the contrary, a lower rate of transpiration is observed due to increase of the amount of bound water and enhancement of osmotic pressure.
3. The physiological nature of the leaves of the graft and the leaves of the level where the graft was inserted are very similar. Leaves of shoots of the top part of the crown are more drought resistant, and the transpiration rate in them is much smaller during the warmest hours of the day.
4. The top, middle and lower levels of the crowns of the mentors exert different influences on hybrid seedlings. This is due to differences in metabolism, water conditions and also to different conditions at various heights of the tree crown. One may suppose that more drought-resistant organisms will be developed in the upper levels of the crown.

Compt. Rend. Acad. Sci. [Paris], 141 (1905), No. 3, pp. 214, 215
Tall morning glory (Ipomoea purpurea) and Quamoclit coccinea were grafted by the author on the sweet potato (Batatas edulis).
     The first 2 are annuals, while the sweet potato in that climate is perennial, developing very slowly and producing tubers only at the end of several years. On the other hand, the 2 plants mentioned first are well adapted to the climate. As a result of these grafts tubers the size of 1 cm. were formed at the end of the first year, the tubers formed when Q. coccinea was used as a scion being smaller than when tall morning glory was used. The control sweet potatoes which had not been grafted produced no tubers.

Magazine of Horticulture, Botany and All Useful Discoveries 5: 446 (December, 1839)
Grafting the Lilac on the Ash.—It is recommended to graft the different species of lilac on the [Fraxinus] Ornus rotundifolia, or flowering ash, in order to retard the appearance of the blooming, and to prolong the season of that beautiful shrub; but whether the lilacs would endure many years on the ash, is very doubtful, since the period of the movement of the sap in the trees is very different: the lilacs expanding their leaves fully a month before the ash trees. (Annales de la Hoc. d'Hort. du Nord, as quoted in Annales d'Hort. de Paris, and translated in Gard. Mag.) [We are of opinion, that the earlier or later period of the flow of the sap, in the stock, would make no material difference in the vigor or health of the scion.—Ed.]

The Farmer's Cabinet 7(8): 260 (March 15, 1843)
Grafting The Lilac On The Ash.—Mr. Scott, of South Carolina, communicates the following to a Southern paper:
This season I grafted the different species of lilac on the common ash, in accordance with some information I received from a friend, (Mr. Wolf, jr.,) while I lived in Paris. I do not recollect to have seen any account of any one having tried the same in this country. We have grafted about three dozen ashes, varying from four feet to ten in height, with the common and Persian lilac; and I am happy to say that the result has exceeded my most sanguine expectations; for we have grown about 25 healthy plants, with branches from one to eighteen inches long, which I hope in an another year, will be covered with bloom. They were grafted in April, after the lilacs had made considerable shoots. I would, therefore advise, that the scions be taken off in January or February, in order to retard their vegetating too soon for the stocks. Would not the pendulous ash form a beautiful object, by having its branches grafted with Persian lilac?—United States Farmer.

Burbidge: Cultivated Plants (1877)
De Candolle, in writing on Olive-worts (see 'Essai Méd.,' p. 204, and Lindl. 'Veg. King.,' p. 616), remarks: "However heterogeneous the Olive-worts may appear as at present limited, it is remarkable that the species will all graft upon each other—a fact which demonstrates the analogy of their juices and their fibres. Thus the Lilac will graft upon the Ash, the Chionanthus, and the Fontanesia; and I have even succeeded in making the Persian Lilac live ten years on Phillyrea latifolia. The Olive will take on the Phillyrea, and even on the Ash; but we cannot graft the Jasmine on any plant of the Olive tribe—a circumstance which confirms the propriety of separating these two orders."

Trans. Mass. Hort. Soc. (1878) p. 99
The habit of the plant is sometimes altered by grafting. Thus Acer eriocarpum, when grafted on the common sycamore [Acer Pseudo-Platanus, L.], attains in Europe double the height which it does when raised from seed. Cerasus Canadensis, which, in a state of nature, is a rambling shrub, assumes the habit of an upright shrub when grafted on the common plum.... The common lilac attains a large size when grafted on the ash; and Tecoma radicans, when grafted on the catalpa, forms a round head with pendent branches, which are almost without tendrils.—Loudon's Horticulturist, ed. 1841, 283.

Thomas: The Cultivator (Feb 1851)
Influence Of Graft On Stock.—Dr. Kirtland says "A graft of the Newtown Pippin will invariably render the bark of the stock rough and black, (the habit of the variety,) within three years after its insertion." Nurserymen, who by digging up trees, become familiar with the growth of the roots, often notice that certain sorts always have certain peculiarities, on stocks of whatever sorts. For instance, the Yellow Bellflower always has fine, fibrous, horizontal roots; the Gravenstein has large, strong, descending roots; the Yellow Spanish Cherry is remarkable for its large heavy roots, whatever the stock may be.

Downing: Grafting and Variability (1845)
But when a graft is taken from one of these trees, and placed upon another stock, this grafted tree is found to lose its singular power of producing the same by seed, and becomes like all other worked trees. The stock exercises some, as yet, unexplained power, in dissolving the strong natural habit of the variety, and it becomes like its fellows, subject to the laws of its artificial life.

Sturtevant, etal.: Influence of stock on scion and vice versa (1880)

Fuller: Influence of stock on graft and graft on stock (1868)
Every nurseryman must have observed that some varieties of the pear have far more fibrous roots than others. So marked is the difference, that the common laborers in the nursery soon learn to distinguish them, and will proceed quite differently in digging the trees of each variety, knowing that one has few long, naked roots, while others have short and numerous fibrous ones. These various forms of roots can not be satisfactorily accounted for in any other way but to ascribe the cause to the influence of the graft. If we take a seedling apple-tree of one or two years old and divide the root into two sections, upon one of which we insert a cion of the Newtown Pippin and on the other one of the Northern Spy, and then plant them both in exactly the same soil and cultivate alike, when, after three or four years, we dig them up, the roots will have a decidedly different appearance.

Transactions of the Iowa State Horticultural Society 14:411 (1880)
INFLUENCE OF STOCK ON GRAFT.
Geo. W. Campbell, of Ohio, gives the following examples, which may have some bearing on the question as discussed in our State:
   A curious and very conclusive instance, showing the effect of the graft upon the stock, occurred in one of my green-houses the present season. Last December my gardener selected a stock of Abutilon Boule de Neige, a well known variety with white flowers, and green leaves, which have never shown any signs of variegation, and after trimming off the side branches, inserted a graft at the height of four feet of Aubutilon Mesopotamicum variegatum. This latter variety is of trailing, or weeping habit, and its foliage intensely variegated with different shades of mottled green and yellow. The graft grew, and retains all its peculiarities of growth and variegation; the stock has also put forth new side-shoots all along its length of four feet below the graft, and nearly all the leaves growing on these shoots from the Boule de Neige stock are marked with clear and distinct variegations of golden yellow, which can only be attributed to the influence of the graft above.
   Upon the other side of the question I will also give an instance of my experience. Two roses were growing near each other; one a variety with very dark crimson, but not well formed, flowers. The other a light blush rose, finely formed, but of a light, undecided color. From the latter variety I inserted buds into the growing shoots of the first named, with this result: The buds grew and retained all their habits of growth and foliage, as well as the form of the flowers; but the color, instead of the light, uncertain blush, was of a rich, dark crimson; nearly, but not quite as dark as the bloom of the stock upon which it was budded.

Sisakian: Vernalization, Mentors and Vegetative Hybridization (1948)
These researches showed that in the majority of cases grafting on to the crown of the mentor causes sharp changes in the activity of the oxidizing enzymes of the grafted phasically young organism, and the direction of these changes are determined by the nature of the mentor. The late varieties of apple trees that were used as mentors, as a rule, caused a higher activity of the peroxidase of the seedling, whereas its grafting on to the crown of an early variety usually led to a lowering of this activity. For example, in the Grushovka/Bellefleur-Kitaika hybrid combination, judging by the peroxidase indices, part of the seedlings turn in the direction of the Bellefleur-Kitaika and part in the direction of the Grushovka. We observed similar changes also in other hybrid combinations.
   We saw a similar picture in another series of experiments in which the buds of hybrid seedlings were grafted on to the crowns of mentors. We showed that the late varieties have a more acute peroxidase and a less active invertase. It turned out that the influence of the properties of the mentor causes a reconstruction of the enzymatic system of the buds. The buds of the late varieties show a more active peroxidase and a less active invertase.

Plesetsky: Hardier Peaches (1948)
The Institute has produced and is now propagating a peach variety, No. 981, which ripens at the end of July (this year it ripened on the 20-23 July, that is to say, simultaneously with the earliest maturing peach varieties cultivated in the extreme South of our country). The average weight of a fruit is one hundred grams. The colouring is bright red. In flavour it is no worse than the best peach varieties cultivated in the South. (Some of the comrades here present can confirm this.) The original parent of this variety perished in the severe winter of 1939/1940. The strain was grafted on various stocks. All grafts perished during the German occupation. Only a graft on a blackthorn survived the severe winters. This year it has yielded a large crop, and this is the case also with the little trees obtained by propagating the grafts on blackthorn. The use of blackthorn as stock has induced radical changes in the peach seed plant: it has become more frost-resistant and earlier maturing, while its flavour has remained good.

The Horticulturist 1(6):290 (December 1846)
INFLUENCE OF THE SCION UPON THE STOCK.— Upon removing the plants from a bed of seedling Canada plums (the wild red plum of our woods), about a hundred of which were budded last summer with the Imperial Gage, Red Gage, and Jefferson plums, and which had made a growth of four or five feet the present season, and were quite stocky, I found that the amount of roots of the budded trees was less than half of those remaining unbudded, and the color was a shade deeper. The Canada plum is remarkable for the amount of roots which it emits, compared with those of the domesticated plum; but in the case of these budded trees, the roots seemed not to have increased from what they were probably last spring, while the tops were larger than those not budded. The influence of the stock upon the scion is a matter which has been much discussed; but I do not recollect ever to have seen any thing upon the influence of the scion upon the stock, or at least as it regards the growth of the roots. The saying of Lord Bacon that "the stock is passive, the scion overruling it quite," seemed here true in a manner I had before thought of. How is it to be explained? Is not something similar seen in the case of pears upon quince stocks? Yours with respect. S. L. G. Saco, Maine, October, 1846.

Northwest Fruit Growers' Association. 79-86 (1899)
Hamilton: Graft Hybridization
...one of my neighbors had a tree of a variety he called the Pound Pear. It was not the same as the fruit thus known in England, but it equally well deserved the name, as the fruit was large, averaging over fourteen ounces each. It was a cooking pear, and, like most of its class, quite unfit to eat in its uncooked state, being harsh, hard and astringent. When ripe (February to May) it was of a yellowish tint, slightly mottled, and with a brownish cheek next the sun. It was of a very blunt conical shape, and a very vigorous grower, its only virtue being its long keeping quality. Desiring to have more of these, my neighbor grafted some cions from this tree on a Mountain Ash, some on a Bartlett, and some more on a Seckel. These cions all bore in due course, and with the following results: On the Mountain Ash stock the fruit was smaller, more conical, at least six weeks earlier, more acid, and had a clearer color, the cheek being red in place of brown. On the Bartlett stock, the pear retained its size, but, in shape and color, exactly resembled the Bartlett. In flavor it was not so harsh as its parent, though entirely unfit to eat uncooked. When cooked, however, it was more palatable than its parent, whilst its season of ripening was unaltered. On the Seckel, its form was rounder, the skin exactly the color of the Seckel, whilst flavor and time of ripening were practically unchanged. Each and every one of these pears, when compared with one another, and with the original parent, showed such marked differences that they would have been taken for different varieties.

Trans. Illinois State Horticultural Society for the year 1902, p. 361
Foster: Propagation of the Apple
...the Whitney or Duchess apple grafted upon an ordinary seedling in our soil will cause it to grow much more vigorously than it otherwise would if left to itself, while on the other hand the Newtown Pippin or Shannon weaken and retard its growth.

Brackett: Influence of Stock on Graft and Vice Versa (1886)
When we graft a tree or insert a bud in a stock and the union is perfected there is a mutual influence maintained between the two. There are instances where the influence of the stock on the graft may be seen, and then again we see the effect of the graft on the stock. For instance, if one hundred apple seedlings are grafted, fifty of them with Ben Davis scions, and fifty with Wine Sap, what nurseryman is there who has had any experience that cannot distinguish one variety from the other by the roots alone.

Proc. Roy. Hort. Soc. (1899)
Mr. Wilks showed samples of the Mannington Pearmain Apple sent by Mr. Peter Veitch, and taken from the original tree which supplied the fruit described by Dr. Hogg fifty years ago. It is a medium-sized Apple, russet in appearance and rugose, with raised lines, though the sample has scarcely a trace of bright coloration, as stated in Hogg's description. The "improved" form was devoid of all roughness, and brightly coloured with yellow and red. It is now widely distributed by grafting, and this improved form is the present recognised Mannington though widely different from the original type. Professor Bailey records an analogous case in America, in that since the original Newtown Pippin has been distributed over the United States it has assumed various forms specially characteristic of Apples growing in the different States, and even in Australia it has also acquired local characteristics.

Michurin: Influence of the scion on the structure of the root system of the stock (1916)
Several strains of roses were grafted on a bed of wildlings of the Rosa canina. Among them was a new Rosa lutea hybrid* which I bred. Three years after the grafting all the roses from this bed were dug up for transplation, and it turned out that, with few exceptions, all the specimens of the grafted Rosa lutea [hybrid] had absolutely smooth roots, without any branchings and fibrils as is usually the case with the Rosa lutea on its own roots. At the same time all the grafts of the other strains had a well-branched and fibrillous root system. Of course, such an example of particularly stong influence of a scion on a stock is an exception. Nevertheless, it is a fact, and horticulturists must bear this phenomenon in mind. Even though it may manifest itself in other plants in a lesser degree, but manifest itself it will all the same.

William Prince, quoted by Mease, 1839.
I had some years ago, 1821, a number of cherry trees killed, but the weeping cherry, a native of Siberia, although budded some height from the ground, remained uninjured; this led me more minutely to examine their roots, and I found invariably, that the roots of all the weeping cherries differed from the roots of other cherry trees, although the stock was the same; the roots of the trees grafted or budded with the weeping cherry being much fuller of fine spreading fibres, and rooting much stronger. Mentioning this fact to a man who keeps a small apple nursery in this place, and on whose veracity I could depend, he told me that the graft of the Siberian crab apple trees, although grafted two feet from the ground, affected the roots, and caused them to become so wiry and hard, and so full of these fine tough fibrous roots, and that they were very different from the roots of other apple trees.

The Horticulturist, 28(330): 355-358 (December, 1873)
Josiah Hoopes
The very moment that an inserted bud or graft commences to granulate and then unite, that moment the two parts of the embryo tree struggle, as it were, for the mastery. That is, certain idiosyncrasies inherent either in the branches of the one, or the roots of the other, will form a leading feature in the mature plant. Abundant proof of this is afforded by examining the roots of nursery-grown apple trees, whether budded or grafted. Take for instance some well-known variety, as the Bellefleur. and the roots will be found uniformly long, slender, and very fibrous; other kinds will prove exactly the opposite.

Michigan State Horticural Society, 1891
The Mutual Influence of the Stock and Graft
A. A. Crozier
The wild crab is frequently said to impart its qualities to cultivated apples grafted upon it. Professor J. L. Budd states,² "that fifteen years ago he grafted the Bethlemite apple on this crab stock, with which it united well and bore good crops of very fair fruit. But of late years, while the apples have the appearance of the Bethlemite, they partake largely of the astringency and pucker of the wild crab and are unfit for eating."

Report of the Iowa State Horticultural Society for 1891, p. 446 (1892)
J. L. Budd: The Bethlemite unites better on wild crab than any other stock. The fruit in one case that came to my notice had the size and appearance of Bethlemite, but the quality of the wild crab. Of about two hundred cions grafted all have the astringency of the wild crab although the union is good.

Report of the Iowa State Horticultural Society for 1873, p 81 (1874)
D. W. Kauffman.—The influence of the graft upon the after-growth of the root is a curious study. Rambo, Ben Davis, Wine Sap, etc., all worked upon the same roots, in two years all have their characteristic roots. Now if the top influences the number and shape of roots, their tendency to fibrousness, to run down to tap roots, to grow out into fine surface roots, etc., why may not the characteristic hardiness of the top be also communicated to the root? Mr. Speer, in his essay read before us, expresses my belief on this subject. After a tree is two three years of age, I believe the seedling root is as hardy as the top.

Cyclopedia of American Horticulture, 1906, pp. 660-661
As a rule, each part of the combined plant—the stock and the cion—maintains its individuality. There are certain cases, however, in which the cion seems to partake of the nature of the stock; and others in which the stock partakes of the nature of the cion. There are recorded instances of a distinct change in the flavor of fruit, when the cion is put upon stock which bears fruit of very different character. There are some varieties of apples and pears which, when worked on a seedling root, will tend to change the habit of growth of that root. Examples are Northern Spy and Whitney apples, which, when grafted on a sort of unknown parentage, tend to make that root grow very deep in the soil.

The Gardener's Monthly and Horticultural Advertiser, Volume 13: 239-240 (August, 1871)
Influence of the Scion on the Stock.
In the early volumes of the Gardener's Monthly, Mr. D W. Adams and others noticed that an apple had its roots singularly modified by the graft which grew on it. The fact is important enough to be kept prominent, as the "philosophy" of the matter has not been explained. We noticed in the Vermont Farmer, recently, Mr. Goodale is quoted in 1863 as noticing the same facts. The Farmer says:
     "Still further, scions have sometimes a peculiar action upon stocks in modifying their habit of growth as regards the roots. Says Goodale, (Maine Agricultural report, 1803, p. 163.) "Let a row of seedling apples be grafted, a part with the Siberian Crab apple, and a part with several free growing kinds like the Baldwin or Greening and it will be found upon lifting them a few years after grafting, that the former may have a much greater amount of roots than either of the free-growing sorts. Let part of a row of young Canada plums (our common wild plum) be budded with the better and more free-growing sorts, like Imperial Gage, Smith's Orleans, or McLaughlin, and after two or three years, upon lifting them, it will be found that the roots of those trees grafted have not, apparently, grown at all since being budded, while those not worked have extended very much. These and similar cases I have repeatedly observed in nursery practice, and there are doubtless other influences also exerted by the stock which are not well understood—for instance, it is said that sometimes an apple, usually free from this defect, has become what is called watercored, in consequence of having been grafted upon a tree, the natural fruit of which was thus affected."

The Gardener’s Monthly and Horticultural Adviser 9(5): 137-138 (May, 1867)
Adams: Are Roots Influenced by the Graft
The Northern Spy will have roots much more numerous and less vigorous, and English Golden Russet will have roots both numerous and vigorous though less in size than the St. Lawrence. So marked is the difference that there would be no danger of mistaking a bundle of one for the other, though only the roots could be seen. Of course these peculiarities are not equally apparent in each single specimen, for some roots have so much individuality that the graft but slightly influences them.
     I recollect several years ago budding a row of Paradise stocks with the St. Lawrence,—mentioned above as having very few and strong roots. A portion failed to "take" and all were left together in the row, and finally all were transplanted at one time. Those with Paradise tops had numerous and fibrous roots, the nominal condition of the Paradise plant. Those with St. Lawrence tops had those great strong roots, few in number, peculiar to that variety.

Northern Nut Growers 1912: 27
Professor John Craig: Yes. Each variety of apple produces its own kind of roots without reference to the seedling stock. That is to say the scion overrules the root in budding or grafting upon one or two year old seedlings.

The Monthly Bulletin, California State Commission of Horticulture. 3(11): 449-455 (November, 1914)
Stocks for Fruit Trees
U. P. Hedrick
There is no doubt, I must say in passing, a reciprocal influence of the scion on the stock. We know certainly, for example, that the form of the roots is much changed by the scion. Thus, in starting apples in a nursery we graft or bud on seedlings which ungrafted would have root systems much the same but at digging time the roots are as diverse as the varieties; Red Astrachan, for instance, has an exceedingly fibrous root system with few tap roots, while on either side of the Red Astrachan row Oldenburg and Fameuse are almost destitute of root fibers, having instead a deep tap-root and two or three prongs.

Nation. Nurseryman 28⁵: 213-214. 1920.
Watson, John. Aphis-resistant apple stocks.—...apple grafts of Bechtel's Crab and of Transcendant will compel a far better root system in two years than scions of Baldwin or Yellow Transparent on seedlings of exactly the same grade.

New York State Agricultural Experiment Station, Tech. Bul. 218 (1933)
Influence of the Cion and of an Intermediate Stem-Piece upon the Character and Development of Roots of Young Apple Trees
Tukey & Brase

Scion: Effect of Graft on Flavour of Fruit. (1898)
However it may be, M. Daniel has grown his plants and conducted his experiments in the full light of day, under the eye of well-known scientific men who bear witness to the genuineness of the work. It is not possible to give more than the following abstract of the results, which have, moreover, been published in detail in the Mémoires of the National Horticultural Society of France:—

1. The reciprocal influence of the scion and of the stock cannot be denied, even though it may not always act with the same intensity.
2. This influence may bear on the general nutrition of the plant, and indirectly on its size, vigour, and resistance to parasites; or it may affect the internal and external morphological character of the plant, including its organs of reproduction, e.g., the fruit.
3. Those variations are frequently of an hereditary character, and appear during the course of the second generation.
4. This effect of the graft offers several practical advantages, viz, the production of larger and "better" fruit and vegetables (such as an improvement in their taste); and the direct production of new varieties, e.g., a modification of the colour of flowers, of the shape of fruit, &c.
5. The effect is more marked in herbaceous than in ligneous plants, and on the progeny of the grafted plant than on the plant itself.
6. The graft, which produces variation in the seed, may be employed to produce new varieties. The variation may frequently be diverted culturally, so at to impart, almost assuredly, after repeated graftings, certain qualities (taste, shape, colour, &c), to a plant which did not originally possess them, and which varies easily under cultivation. As regards other plants, the graft still affords the means of obtaining variation, however difficult it may be; and as soon as the change is observed, it can be pursued in the desired direction, and with good results

A "Mixed" Method of Grafting (1898)
The dwarf Soissons Haricot bean was further dwarfed when grafted onto the vigorous Black Belgian Haricot.

The Gardener's Monthly and Horticultural Advertiser, 10(11): 330-331 (November, 1868)
Berckmans: Dwarf Peach Trees
Orchard house culturists complained some years since, that the health of the Peach trees trained for pot culture, was impaired after a fair season of fruiting, by the cramped space the roots had to occupy. This remark led me to the idea of taking the seedlings of the Italian Dwarf peach as stocks whereupon to work the early market varieties upon, and to endeavor to produce really Dwarf Peach trees of any given variety, without the necessity of root pruning, etc.
     I consequently budded several seedlings of the Italian Dwarf with Hale's, Troth's, Amelia, China Cling, etc. Last year the buds started off finely, and I was anticipating for the ensuing fall some well formed Dwarf Peach trees, but contrary to my expectations, the buds kept growing until by fall they averaged seven feet high, with bodies two and a half inches in diameter at the junction of bud and stock, while the latter attained the same heavy growth. The remaining seedlings in the same row being left unbudded averaged one inch in diameter at the ground.
     This unexpected result proved that in the case of the Peach the graft influences the stock solely, and the latter has little if any influence upon the former; this being made evident by the stock of the ordinary peach assimilating itself entirely to the peculiar growth of the Italian Dwarf when budded with that variety.

Gardener’s Monthly, 9(3): 78-79 (March 1867)
Stayman: Influence of the Graft on the Stock
Here we find that the graft increases or retards the growth of the stock depending upon its vigor. For instance, if we graft a very vigorous variety on a dwarf stock it increases the stock's natural growth, but if we graft a very dwarf variety on a vigorous stock it retards the stock's natural growth.

Saul: Rose Stocks (1850)
The Crimson Boursault stock should be used with caution. I am aware that some growers speak highly of it, and have used it extensively; but it is nothing more than a good nurseryman's stock, namely, one on which delicate roses will grow beautifully for a time, but on which they will soon perish. Many strong-growing Perpetuals, Bourbons, Noisettes, &c., will grow well upon it, though not so well or so long as on the foregoing. This stock is softer, more subject to decay, and, in every point worth considering, inferior to the Manettii: it should, consequently, give way to the latter. For the beautiful and delicate varieties of Perpetuals, Bourbons, Noisettes, Teas, &c., it is infinitely inferior to Manettii, and should never be used where the latter stock can be obtained.
     Some few years back nurserymen were in the habit of growing peaches on what is called the Brompton Plum stock, a very free growing variety, on which the peach grew beautifully for a season, but in many instances they had commenced decaying before they left the nursery: very few respectable nurserymen grow this stock now. The Crimson Boursault occupies the same place as a rose-stock which the Brompton Plum does as regards the peach. Gardeners who would object to have their peaches worked upon the latter stock, should pause and consider what sorts of roses they would have worked upon the other.

Burbidge: Curiosities of Grafting. The Garden, 8: 460 (Nov. 27, 1875)
Of late years many experiments have been made in grafting the Grape Vine, and some useful knowledge as to the influence of stock on scion and scion on stock has thus been gained. There is one thing, however, which is apt to be forgotten in records of grafting, but which I am fully convinced affects the results obtained much more than is generally supposed. For example, a stock which is allowed to bear foliage and fruit of its own, and the same stock headed off and only allowed to bear the leaves and fruit of the scion, give very different results, as the stock which is allowed to retain its own leaves naturally retains more of its own constituent juices and constitutional characteristics than in the other case.
     It appears to me that the whole question of the reciprocal influence of scion and stock hangs on constitutional vigour, that is to say, a strong-growing scion will overrule and add vigour to a feeble stock; while, on the other hand, it is well known that a moderately vigorous stock strengthens and invigorates a feeble scion. The effects of constitutional vigour, to whatever cause, it may be due, is seen when three or four varieties—Plums, Roses, Apples, or Pears—are worked on the same stock. Instances are on record where stocks influence the habit of the same plant in a most remarkable manner.

Burbidge: Cultivated Plants p. 62 (1877)
In the 'Revue Horticole,' vol. for 1873, a curious statement is made, to the effect that an Italian horticulturist, M. Zenone Zen, has contributed a paper to the Royal Institution of Venice, in which he declares that, after long study and experiment, he has succeeded in producing varieties of Roses by budding in a certain manner. Two well-known botanists were appointed to see M. Zen's mode of budding, but they could not detect anything unusual in his manipulations; notwithstanding which, when the plants operated on flowered, the blooms were different in form, size, and colour, from the varieties whence the buds had been taken, and these new characteristics become intensified with the age and vigour of the plant. The varieties produced are said to be permanent, and may be perpetuated by budding, layering, or grafting in the usual manner; and if the variety becomes lost, it can be reproduced by performing the original operation of budding again in M. Zen's secret manner, or under like conditions. [Also discussed in the Journal des Roses, Sept. 1904]

A Textbook of Botany for Colleges and Universities (1911)
The influence of the stock and the scion upon each other. — Many cases are now known in which either the stock or the scion is influenced by the other, so that a part of the original individuality is lost; particularly in evidence is the influence of the stock upon the scion.¹ Such differences may manifest themselves in physiological behavior, as in changed respiration and synthesis, and particularly in reproductive phenomena; or there may be changes in form, in color, or in chemical composition, as when an apple scion grafted on the wild crab bears more acid fruit. The best known changes concern the time of fruiting; a variety of the apple that requires ten or fifteen years to come into bearing from seed may bear in a year or two if a twig from a sapling is grafted on au old stock, while a twig from an old stock grafted on a sapling does not fruit for years. Some late apples ripen earlier when grafted on a stock of an early variety. Certain species of Citrus are more productive when grafted on Citrus trifoliata than when growing independently. When the morning glory, which is an annual, is grafted on the sweet potato, which is a perennial, the latter develops its characteristic tuberous roots much earlier than otherwise, thus giving an excellent illustration of the influence of the scion upon the stock. When the sunflower, which is an annual, is used as a stock for the Jerusalem artichoke, which is a tuberous perennial, the artichoke scion develops aerial tubers and the sunflower stock is characterized by a large development of secondary wood.

Vick's Magazine, 8: 273 (September 1885)
STOCK AFFECTING THE GRAFT.
In an interesting and instructive article in the Revue Horticole, on the subject of the "Direct influence of the stock upon the graft," by F. SAHUT, which, however, it is not our purpose to notice fully, we find the following reference to the Tecoma—Bignonia radicans and other species:
     "The climbing Tecomas, when grafted upon the Catalpa lose the climbing habit and form bushes which, by compensation, flower very much more freely than upon their own roots." Of the Chionanthus, or White Fringe tree, he says: Chionanthus Virginica grafted on the Ash, flourishes abundantly, but never fruits, while it fruits on its own roots."

Plant Mol Biol. 2003 Nov; 53(4): 493-511.
Rootstock effects on gene expression patterns in apple tree scions.
Jensen PJ, Rytter J, Detwiler EA, Travis JW, McNellis TW
Like many fruit trees, apple trees (Malus pumila) do not reproduce true-to-type from seed. Desirable cultivars are clonally propagated by grafting onto rootstocks that can alter the characteristics of the scion. For example, the M.7 EMLA rootstock is semi-dwarfing and reduces the susceptibility of the scion to Erwinia amylovora, the causal agent of fire blight disease. In contrast, the M.9 T337 rootstock is dwarfing and does not alter fire blight susceptibility of the scion. This study represents a comprehensive comparison of gene expression patterns in scions of the 'Gala' apple cultivar grafted to either M.7 EMLA or M.9 T337. Expression was determined by cDNA-AFLP coupled with silver staining of the gels. Scions grafted to the M.9 T337 rootstock showed higher expression of a number of photosynthesis-related, transcription/translation-related, and cell division-related genes, while scions grafted to the M.7 EMLA rootstock showed increased stress-related gene expression. The observed differences in gene expression showed a remarkable correlation with physiological differences between the two graft combinations. The roles that the differentially expressed genes might play in tree stature, stress tolerance, photosynthetic activity, fire blight resistance, and other differences conferred by the two rootstocks are discussed.

Jour. Franklin Institute 13: 192 (1832)
The Seckel pear may be cultivated, and will flourish, on almost any species of soil; it should always be grafted or inoculated on the wild pear tree, as grafting on the quince tree subjects it to the same diseases with which this tree is generally affected in this country.

Botanical Abstracts 7(1): 44-45 (February, 1921)
290. Watson, John. Aphis-resistant apple stocks. Nation. Nurseryman 285: 213-214. 1920.—The nurserymen of America must come to appreciate to a greater extent the importance of securing nursery stock which will be resistant to aphis injury. The influence of the stock upon the scion as well as the influence of the scion on the stock is recognized. For instance, apple grafts of Bechtel's Crab and of Transcendant will compel a far better root system in two years than scions of Baldwin or Yellow Transparent on seedlings of exactly the same grade.—Of all aphis-resistant stocks the Northern Spy is the best. It is largely used in England, South Africa, Australia, and New Zealand. The suggestion is made that the time will probably come when California will use nothing else. In Australia, where woolly aphis is a prolific pest, the nurserymen have developed more than 25 varieties of resistant stocks, but Northern Spy furnishes fully 95 per cent of the apple stock used.— Methods for propagation of the stock are given, which are much like those used for Paradise and Doucin stocks.—J. H. Gourley.

Also, Epigenetics, Gene Silencing, RNAi