Cytology of Development of Abnormal Endosperm in Philippine Makapuno Coconuts

Abstract

SUMMARYThe cytology of development of the buttery kernel (endosperm) in the Philippine makapuno coconuts has been studied. Though the first formed cellular endosperm is predominantly triploid, higher levels and grades of ploidy like 6 n, 9 n, 12 n, 24 n and 48 n (and above) characterise the maturing endosperm. The cytological situation in early stages of the makapuno endosperm is comparable to that in other coconut varieties, particularly the dwarf coconuts with which they share the relatively higher levels of polyploidy, presence of 2 n and 9 n nuclei and the greater frequency of mitotic abnormalities including considerable stickiness of chromosomes.The later stages of development of the makapuno endosperm characterised by unlimited growth and proliferation, accompanied by high polyploidy, increase in frequency of abnormalities, cessation of normal mitosis, onset of amitosis, attainment of high nuclear polymorphism, appearance of characteristic cell inclusions, etc. followed by degeneration of the nuclei...