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 (P0.05) in pollens, slightly lower indole-3-acetic acid (IAA) content (P>0.05), significantly higher abscisic acid (ABA) content (P0.05),雌蕊中的赤霉素(GA3)含量显著低于二倍体(P0.05),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.