【摘要】 本试验在花前和花后不同时期使用了不同种类的生长调节剂,分析了有籽枇杷和无籽枇杷果实在发育过程中三种内源激素(生长素、脱落酸和细胞分裂素)的变化。结果表明,开花前赤霉素处理形成的无籽果实不能长大的原因是无籽果实在细胞分裂期缺少细胞分裂素和生长素。同时,本文还探讨了枇杷果实发育和单性结实的机理。更多还原

【Abstract】 The experiment was conducted with growth regulators at different times, assaying hormones and the development of seeded and seedless fruit to clarify the mechanision of fruit development and parthenocarpy in loquat. Experimental results showed that the development of loquat fruit could be divided into three phases: retarded growth phase ( stage 1 ) , cell rapid-division phase ( stage 2 ) , cell expansion and maturation phase( stage 3 ) .The trees were sprayed with GA3 ( 300ppm ) before bloom, with the result that all of the fruits were parthenocarpic and smaller and earlier ripen than the control. The size of fruit was not increased by treat-ments with IAA,6-BA and GA3 before bloom.The weight of fruit increa-sed from 12.70g to 18.89g sprayed with GA3 (300ppm) twice after bloom. H/D of fruit increased to 1.338 and 1.367 treated with GA3/IAA/6-BA (300/20/100 and 300/20/300ppm ) respectively, 1.014 in the fruit sprayed with MH and GA3 in late March grew normally, but its seed development was inhibited.The change of endogenous hormones in the normal fruit was studied. The first and second peak of IAA, CTK appeared at stages Ⅰ and Ⅱ respectively. Then decreased. ABA levels appeared high during stage Ⅰ and Ⅲ,then dropped gradually to the lowest level during stage Ⅱ.There was a similar change of endogenous hormones in seedless fruit ( GA3 application)in stage Ⅰ and Ⅲ. while there were no peaks of IAA and CTK in stage Ⅱ . which cause cell division and expansion of fruit treated with GA3 was inhibited.更多还原