Preliminary Pollen Analysis of Some Apple Cultivars in Kashmir: Towards Understanding the Apple Pollen Morphology

Abstract

Kashmir Valley, a North Western state in India, represents the richest repository of apple germplasm of about 200 cultivars besides some unknown genotypes of seedling origin. Among the rich germplasm resource, sixteen apple cultivars belonging to two commercially important groups with one group having Delicious as a suffix and other group having Ambri as a suffix were examined for the first time based on pollen grain surface morphology using scanning electron microscopy for genotype differentiation. Most of the air-dried apple pollen grains were elliptical and tricolpate with three germinal furrows extending almost the full length of the pollen grain. However, round and tricolpate pollen grains were observed in cultivars Kullu Delicious, Oregon Spur, Reeka Red, and Silver Spur. Striation pattern of the pollen grains varies from cultivar to cultivar. Mostly, the striations extend from one end of colpi to another end, but in case of Cross Delicious, the striations were irregular and form network-like structures. Pores on the exine surface also showed great variations among the cultivars. The cultivars like Oregon Spur, Silver Spur, and Reeka Red are said to be the sports of Delicious, but from the results of scanning electron microscopy, these resemble Kullu Delicious in terms of pollen shape, striation pattern and pores on the exine surface.