21 Dec Polyembryony in Horticulture and its significance
बागवानी में पॉलीएब्रीयोनी या बहुभ्रूणता और इसकाा महत्व में Polyembryony is the occurrence of more than one embryo in a seed which consequently results in the emergence of multiple seedlings. The additional embryos result from the differentiation and development of various maternal and zygotic tissues associated with the ovule of seed. Earlier, polyembryony is said to have an abnormal feature but now it is considered as a desirable character in citrus, mango, jamun, rose apple, almond, etc. to obtain true to type planting material. In the usual process of plant reproduction, egg cell (female) of ovule fertilizes with the male gamete which in turn culminates in embryo (zygotic). On the other hand, in some of the crops, somatic cells of ovule (usually nucellus) start producing embryo without fertilization results in the occurrence of more than one embryo in the seed (polyembryony). The formation of embryo without sexual process is called apomixis (Apo=away from+ mixis = act of mixing) and seed is called apomictic seed, whereas the condition is called polyembryony. In most of the cases, sexual embryo and nucellar embryo developes simultaneously which is known as facultative polyembryony. Polyembryony was first reported by Leeuwenhoek in citrus as early as 1719 and the different cases of polyembryony in plants were studied by Braun in 1859. In 1878 Strasburger demonstrated...