内源激素对同源四倍体黑皮冬瓜自交花粉萌发生长的影响

摘要

[Objective]To study the relationship between pollen germination and growth of autotetraploid Benincasa hispida (Thunb.) Cogn. and endogenous hormones, and explore new ideas for understanding the low fertility mechanism of autotetraploid B. hispida.[Method]Taking autotetraploid and diploid B. hispida as materials, germination and growth of self-pollinated pollen in pistil and the contents of endogenous hormones in pollens and pistils were studied.[Result]The germination rate of self-pollinated pollen of autotetraploid B. hispida was low on the stigma. Pollen tube growth was slow. There were some abnormal phenomenons during growth of pollen tubes, such as uneven thickness, nodule formation, swelling at the tip, two pollen tubes in one pollen, distorted and folded pollen tubes. Compared with diploid B. hispida, the pistils and pollens of autotetraploid B. hispida had significantly lower zeatin riboside (ZR) and isopentenyl adenosine (IPA) contents (P<0.01), significantly lower gibberellin A3 (GA3) content (P<0.05) in pistils, silightly lower gibberellin A3 (GA3) content (P>0.05) in pollens, slightly lower indole-3-acetic acid (IAA) content (P>0.05), significantly higher abscisic acid (ABA) content (P<0.05), and significantly lower ratio of (IAA+GA3+ZR+IPA) to ABA contents (P<0.01).[Conclusion]The endogenous hormones in the pistils and pollens of autotetraploid B. hispida regulate pollen germination and growth and cause abnormal phenomenons in pollen tubes, which is one of the reasons for the low fertility of autotetraploid B. hispida.%[目的]探讨同源四倍体黑皮冬瓜Benincasa hispida(Thunb.)Cogn.花粉萌发生长与内源激素的关系,为同源四倍体黑皮冬瓜自交低稔性机理研究开拓新思路.[方法]以同源四倍体及其原二倍体黑皮冬瓜为试材,对自交花粉在雌蕊上的萌发与生长情况及花粉与雌蕊中内源激素含量进行比较研究.[结果]同源四倍体黑皮冬瓜自交花粉在柱头上的萌发率低,花粉管在花柱中生长缓慢,且花粉管在生长过程中易出现粗细不均匀、结节、先端膨大、双花粉管及扭曲、折叠等现象.同源四倍体黑皮冬瓜花粉和雌蕊中促进花粉萌发生长的内源激素玉米素核苷(ZR)和异戊烯基腺苷(IPA)含量极显著低于二倍体(P<0.01),吲哚乙酸(IAA)含量略低于二倍体(P>0.05),雌蕊中的赤霉素(GA3)含量显著低于二倍体(P<0.05),花粉中的GA3含量略低于二倍体(P>0.05),而抑制生长类激素脱落酸(ABA)含量显著高于二倍体(P<0.05),w(IAA+GA3+ZR+IPA):w(ABA)极显著低于二倍体(P<0.01).[结论]同源四倍体黑皮冬瓜花粉和雌蕊中内源激素调控了花粉萌发生长,导致花粉管出现异常现象,是引起同源四倍体黑皮冬瓜自交低稔性的原因之一.