212 



THE AGRICULTURAL NEWS 



July 6, 1912. 



FRUITS AND FRUIT TREES. 



THE EMBRYONY OF THE MANGO. 



Two articles were published in Vol. VIII, of the Agri- 

 cultural Xeics, on pages 187 and 228, which were concerned 

 with the fact that both monoembryonic and polyembryonic 

 seeds of the mango are known. This means that there are 

 not only varieties of this plant which produce seeds that give 

 rise to one seedling, alone, but that there also exist varieties 

 with seeds from which as many as six to eight, and even 

 thirty, plants may spring. The former of the articles gave 

 an account of observations on the polyembryony of the 

 mango, made by J. Belling and published in the Annual 

 Jieport or the Florida E.ijieriment Station for 1908. In this, 

 attention is given to the fact that where more than one seed- 

 ling comes from one seed, one of the seedlings is the result 

 of pollination and consequent fertilization, while the others 

 arise in a purely vegetative way — much in the same manner 

 as suckers are formed, and cuttings grow. 



An addition to the interest of the subject is afforded in 

 an article by P. J. Wester which appears in the Philipjjiyie 

 Agricultural Review for February 1912. This commences 

 by making references to other well-known examples of plants 

 with polyembryonic seeds, such as the orange and tangerine 

 and the rose-apple (Eugenia Jamb'is). and proceeds to refer 

 to the work of Webber and Swingle, in which, when several 

 seedlings developed fiom one seed obtained by crossing the 

 orange and Citrus trifoliata, one only shewed hybrid charac- 

 ters, the others exhibiting the characteristics of the mother 

 plant, alone; thus confirmation was obtained of the purely 

 vegetative origin of all but one. It is then pointed out that 

 the consideration of polyembryony in the mango is no new 

 matter, for Gartner had already noted the peculiar structure 

 of the mango seed, about a century ago, though he probably 

 did not recognize its significance, the matter remaining for 

 discussion at some length by lieinwardt, a few years after- 

 ward. Later references to the subject are made by Schacht, 

 Strasburger and Cook, and the places where these, as well as 

 others, are to be found are cjuoted usefully in Westers article. 



Reinwardt was aware of the existence of monoembryony, 

 as well as of polyembryony, in the mango, though later 

 investigators appear to have paid very little attention to the 

 former. The significance of the matter is that plants true to 

 type are more likely to be obtained from seeds producing 



more than one seedling, than from seeds giving only one 

 plant; for in the former case, all the sprouts but one are 

 i.f vegetative origin, and thereiore little inclined to variation. 

 This is illustrated practicully in a most interesting way by 

 the circumstance that, in .Jamaica, Florida and the Philip- 

 pines, where the varieties of mangoes nsually cultivated are 

 polyembryonic, these reproduce themselves true to seed; 

 whereas all the grafted mangoes introduced into Florida from' 

 India (except that called Cambodia), which are monoem- 

 bryonic, have given seeds that afford [jlants showing much 

 greater variation from the mother parent than is exhibited 

 by polyembryonic kinds. AVester quotes C. Maries as saying, 

 with respect to the Indian varieties, in their own country: 

 'If the seed from the best and finest sorts are (sic) planted, 

 the chances are that fifty per cent, will be as good as the 

 fruit planted, a few better, and the rest worse.' The matter 

 receives further illustration in the significant circumstance 

 that, of all the varieties introduced into Florida from the 

 East, the only polyembryonic form -Cambodia, mentioned 

 above— is the sole kind that reproduces itself truly from 

 seed. 



Wester, in continuing his article, mentions Belling's work, 

 to which reference his been made already, and draws atten- 

 tion to the apparent conclusion of this observer, namely 

 that monoembryony is a result of the practice of grafting for 

 several generations, rather than an inherent botanical charac- 

 ter. It has occurred, however, to Wester to suggest that, 

 from the data collected, 'the species Jfangifem indica, L.', 

 may be divided into two great types: one, the monoembryo- 

 nic. to which belong most, if not all, of the mango varieties 

 in India; the other, the polyembryonic type, the mangoes 

 belonging to which transmit their characters to their pro- 

 geny.' He realizes, nevertheless, that much more study of 

 it is required before the subject can be given a definite 

 conclusion. 



The second of the articles mentioned at the commence- 

 ment of this contains information supplied by Mr. Jones 

 Curator of the Dominica Botanic Station, which would tend 

 to show that experience there has apparently demonstrated 

 that the polyembryoric manooes .«how much greater varia- 

 tion in type than in the Philippines; probably because the 

 seedling that is the result of fertilization is the stronger, and 

 therefore the one that is allowed to survive. Useful sugges- 

 tions for further work are made bj' Mr. Jones. 



