Pollen characteristics, pollination behaviour and pollinizer compatibility of some exotic and indigenous almond [Prunus dulcis (Miller) D.A. Webb] genotypes

Abstract

Pollination is the most critical and complex part of fruit production, particularly in cross pollinated crops like almond, and it is affected by pollen characteristics. In the present study 100% pollen viability was observed when stained by acetocarmine for all considered genotypes, except GP-17 (99%). Optimum stigma receptivity was observed for two days before anthesis, on the day of anthesis and one day afterwards all the stigmas remained receptive. In open pollination, maximum fruit set was noted in Primorskij (32.37%) with mini- mum in Makhdoom (17.96%). No fruit set was observed in any of the genotypes by self-pollination, confirming the self-incompatible nature of all tested genotypes. In cross pollination, fruit set was found between 0.00 and 42.84% for different cross combinations. Makhdoom, Pranyaj, Shalimar, Waris, Nonpareil, Waris, Waris and Shalimar yielded maximum fruits when cross-pollinated with IXl, Merced, Drake, Primorskij, Pranyaj, Nonpareil, Shalimar, Makhdoom and Waris, respectively. No pollen tube growth was observed in the style when genotypes were crossed with their own pollen. In crosses between IXL and Nonpareil, pollen tube growth was arrested in the styles. In compatible crosses, the pollen tube reached the base of the style after different times following pollination.