High Temperature Effects on in vitro Pollen Germination and Seed Set in Field Pea

Prevailing global warming has challenged agricultural production such that it is paramount to evaluate crop cultivars that tolerate increasing temperatures. Heat tolerance in many crops has been screened by examining in vitro pollen germination. The objectives of this study were to determine the effects of high temperature on in vitro pollen germination and pollen tube growth in Pisum sativum L., a crop species adapted to relatively cool temperatures. To evaluate genotypic differences, pollen from 24 cultivars grown in the field was collected and subjected to control (24 °C) and high temperature (36 °C) regimes for 24 h. The latter reduced both in vitro pollen germination percentage and pollen tube growth. Moreover, cultivars differed significantly for in vitro germination of their pollen at high temperatures but not for pollen tube length of germinated grains at 36 °C. In vitro pollen germination was not correlated with seed set parameters of seven of the same cultivars tested in growth chambers at contr...