Seventeenricevarietiesandhybridsofdifferenttypes(indica,japonica,javanica,indicahybrid,japonicahybridandinter-subspecifichybrid)wereevaluatedtodeterminetheeffectoftemperatureonpollenfertilityininter-subspecfichybrids.Thepollenfertilityofinter-subspecifichybridswasgreatlyreducedwhenaveragedailytemperaturedroppedto22.0-23.0℃atmeiosisstage,andtheextentofpollenfertilityreductionvariedgreatlywithrespecttodifferenthybrids.However,thepollenfertilityreductionofindicaandjaponicahybridsandconventionalvarietieswasnotobviousunderthesameregimeoftemperatureconditions.Whentheaveragedailytemperaturedroppedto20℃.thepollendevelopmentofconventionalvarietiesandhybridswasalsoaffected.Correlationanalysisrevealedthatthereexistedapositivecorrelationbetweenpollenfertilityandaveragedailytemperature.Asignificantdifference(P<0.01)wasalsofoundbetweenthetwocorrelationcoefficientsi.e.inter-subspecifichybridsandconventionalvarieties.Temperatureatmeiosisstageofpollenmothercellwasakeyfactorinpollendeveloping,andthepollenfertilityofinter-subspecifichybridswasmoresensitivetolowtemperaturethanthatoftraditionalvariety.
