Chromatin stickiness and abnormal spindle resulting in meiotic irregularities and pollen sterility in meconopsis aculeata royle from the Northwest Himalayas

Abstract

Detailed meiotic investigations were performed in three accessions of Meconopsis aculeata scored from high altitudinal regions in the Northwest Himalayas. These accessions exhibit the same chromosome number of n=28 and exist at tetraploid level. We report here the occurrence of chromatin stickiness and abnormal spindle activity in the presently studied accessions. Consequent to chromatin stickiness and abnormal spindle activity, various irregularities were observed at different stages of meiosis. These include inter-bivalent connections, out-of-plate bivalents, laggards and chromatin bridges during anaphases/telophases resulting in the formation of abnormal sporads like triads, tetrads with micronuclei and polyads. The products of such sporads yielded heterogeneous-sized fertile and sterile pollen grains. Chromatin stickiness and abnormal spindle activity causing meiotic irregularities, abnormal sporads and pollen malformation seem to be the result of low temperature stress conditions prevailing in the area when the plants enter the flowering stage.