Division of Genetics’, Indian Agricultural Research Institute, Delhi-12
This paper deals with the study of seed development in crosses between Gossypium arboreum (2n=26, A genome) and G. raimondii (2n—26, D genome), the possible progenitors of cultivated allopolyploid cottons (G. hirsutum and G. barbadense 2n=52, AD genome). G. arboreum and G. raimondii arc cross-incompatible. The cross G. arboreum X G. raimondii fails due to the breakdown of the hybrid endosperm. Occasionally, mature seeds contain somewhat undifferentiated embryos capable of giving rise to hybrid plants. The cross G. raimondii X G. arboreum fails due to differences in the style length.
