Gardeners' Chronicle, 32(832): 419 (December 6, 1902)
EFFECTS OF GRAFTING

In the Comptes Rendus for September 22, we find a note by M. LUCIEN DANIEL, on a modification produced in Scopolia carniolica by grafting it on the Tomato. The author remarks that it is already known how, by certain processes, some plant characteristics can be modified, and particularly, that the flowering season may be advanced or rotarded by heat. "Further," writes M. DANIEL, "by sowing out of season, a plant may be induced to flower at an unusual time. By the entire suppression of the blooms as they appear, an annual plant is turned into a biennial, if sheltered from winter cold (Reseda). On the other hand, certain perennials with annual herbaceous aerial stems, sometimes retain through the winter certain of these stems, which thus become truly perennial. And yet again, by hybridisation, in some plants the continuously flowering habit is obtained, that is they flower and fruit twice in the same year (Rose, Strawberry, &c.)". In order to ascertain what part grafting may play with regard to such modifications in the habits of plants, M. DANIEL has for a long time been making experiments on this subject. In 1892 he demonstrated that, apart from precocity or lateness in the blooming of the graft, it was possible by direct grafting or by sowing seed after grafting to distinctly alter certain habits of the graft. Thus he caused some biennial specimens of Salsafy to become perennial by grafting them on Scorzonera, and annual Tobacco was made to become biennial by grafting it on the Tomato. But in this case, it must be understood, the stock did not flower in the same year that it was grafted. From seedling plants of black Belgian Haricot grafted upon Haricot de Soissons gros, he raised a race of climbing Haricots which now are almost constant. But, so far as his experience goes, there has been no former description given of any plant that has assumed the climbing habit as a consequence of grafting, or a single instance of a herbaceous plant regaining life and vigour consequent upon grafting. This year he certainly observed these two varieties of phenomena consequent upon grafting Scopolia carniolica on young plants of Tomato. Scopolia carniolica is grown in botanic gardens as a herbaceous perennial, and is one of the most precocious in spring. After fruiting the aerial stems keep green for some time, withering gradually and remaining quite faded during May. The Tomato, on the contrary, is then starting and grows vigorously. Although these two plants are both Solauaceous, they belong to two different groups; the former to the Hyoscyameae; the second to the Solanums. On May 1 last, M. DANIEL grafted on to the young Tomato, the aerial shoots of the Scopolia that were about to wither. The graft succeeded, and in spite of the age of the grafts, and in spite of their spring-flowering, they recommenced life, put forth new buds, and then leaf branches, that are still green and fairly vigorous. Further, one of the grafts actually formed an inflorescence which bore three normal flowers. The fruits formed as in spring. These experiments lead to the following conclusions: (1). Similarity of habit between stock and graft is not absolutely essential to successful grafting. (2). The aerial stems of Scopolia can be regenerated when senile decay seems near, by grafting them on young and strong Tomatos. (3). Modified grafting often greatly alters the habits of plants, and in the Scopolia may cause a second blooming season in the year; that is to say, to give the plant a perpetual habit.

Gardeners' Chronicle, 32(835): 469-470 December 27, 1902
M. DANIEL'S EXPERIMENTS IN GRAFTING

We have on several occasions reported on the experiments made by M. DANIEL in grafting, and the results obtained by him. The Journal de la Société Nationale d'Horticulture de France for September last also gave an interesting paper, by M. ED. BORNET, on the experimenter and his work, from which we take the following particulars:—

M. L. DANIEL has for ten years made grafting his special study. Although the practice has been known for centuries, the full explanation of the results of it has but lately been attempted. M. DANIEL, by methodised trials, has done much to explain the biological relations between the stock and the graft, one of his most important series of experiments being chronicled under the title: 'Variation in the Graft and Heredity of Acquired Characteristics,' and published in 1809. His affirmative reply to the question concerning this heredity should be found interesting from a biological standpoint, and also for the practical application that may be made of his theories, agriculturally and horticulturally.

Some of these variations are produced directly on the grafted plants by the disturbance in the process of general nutrition caused by the graft. M. DANIEL examined them in detail, and showed by many experiments that two causes acting simultaneously, or, in a contrary sense, modify the nutrition of the graft and the stock ; these are:—

1. The swelling consequent upon the operation.
2. Differences between the functions exercised in the stock and in the graft.

Other more important variations are caused by mutual reaction between the stock and the graft. This is the newest, but as yet, the least extended side of M. DANIEL'S researches. In fact, the information is not yet abundant, firstly because the specific influence seems less marked than does the disturbance of the general nutrition, and secondly because the trials have not been directed to these matters. But most of the facts ascertained were discovered by M. DANIEL. These are some of them:—Alliaria, grafted on green Cabbage, partly lost its scent, and in part the odour of the green Cabbage became combined with the alliaceous scent, whilst the flavour itself was modified. In grafting the Turnip on the Cabbage, and inversely, there was an increase or decrease in the sugary flavour of the roots of some specimens. Similar variations were observable in the development, form and structure of the vegetative organs, in the inflorescence, the flower and the fruit. Thus the long violet Aubergine, grafted on to the ribbed-fruited Tomato, produced rounded, ribbed fruits.

The experimenter sowed seed furnished by the grafts that appeared not to be immediately influenced by the stock, and some from those plants on which the specific influence was directly shown. In three instances he obtained examples of the transmission of certain characters acquired by the graft to its descendants during several successive generations. He is convinced that in many cases grafting will prove an effectual way of influencing variations in the plant under treatment. The variations obtained will be preserved or increased by the usual methods.

In a report presented to Congrès de l'Hybridisation de la Vigne, at Lyons, in November 1901, under the auspices of the local Société de Viticulture, M. DANIEL collated facts relative to specific variations in the graft which he termed asexual hybridisation, and furnished instances applicable to the Vine.

Daniel bibliography