【目的】荚是为大豆籽粒发育过程中提供同化物的暂存源器官。大豆荚脱落率高是制约大豆生产的重要因素之一,为进一步探讨化学控制技术提高大豆产量的内在机制,通过研究叶面喷施2种调节剂对大豆荚生理代谢及离区脱落纤维素酶基因(Gm AC)表达的影响,为大豆高产、优质、高效栽培提供理论依据。【方法】以大豆品种抗线6号(Glycine max)为材料,在R1期叶面喷施60 mg·L^-1促进型调节剂2-N,N-二乙氨基乙基己酸酯(DTA-6)和50 mg·L^-1延缓型调节剂烯效唑(S3307),以喷施清水为空白对照,于喷药后35、42、49和56 d选取处理和对照中的大豆豆荚,测定荚中可溶性糖、蔗糖、淀粉、丙二醛(MDA)、过氧化物酶(POD)、脱落纤维素酶(AC)等生理指标。喷药后第5天用剪刀剥取同一处理大豆荚基部与茎相连离层区组织,采用RT-PCR方法测定脱落纤维素酶基因(Gm AC)的表达量。【结果】除喷DTA-6后35 d处理的可溶性糖含量高于对照外,其余取样时期DTA-6和S3307处理均显著降低了荚中可溶性糖含量。在喷药后35—49 d,DTA-6和S3307处理荚皮中蔗糖含量低于对照,而在喷药后56 d高于对照。除喷S3307后42 d处理的淀粉含量低于对照外,其余时期DTA-6和S3307处理均增加了荚皮中淀粉含量。在喷药后35、49和56 d DTA-6和S3307处理降低了荚皮中MDA含量。在喷药后35、42和56 d DTA-6和S3307处理提高了荚皮中POD活性。S3307处理在喷药后35、49和56 d降低了荚皮中AC活性,DTA-6处理在喷药后42—49 d降低了荚皮中AC活性。DTA-6处理下调了大豆离区Gm AC的表达量,而S3307处理大豆离区Gm AC的表达量上调。DTA-6和S3307处理均有效地改善了大豆单株荚数、荚粒数、百粒重等产量性状,2012年和2013年产量分别比对照高6.23%、1.41%和4.83%、5.30%。【结论】DTA-6和S3307处理有利于大豆荚皮中同化物的转运和积累,提高保护酶活性
【Objective】 Pods are important source organs for temporary reserve photosynthate in soybean grain growth progress. It is a key factor of pods abscission to restrict soybean production. In order to investigate the internal mechanism of chemical control technology to improve soybean yield, this study used two plant growth regulators to discover the different effects on physiological metabolism in pods and the expression of abscission cellulose enzyme gene(Gm AC) in the abscission zone. This study will provide a theoretical basis for high-yield, high-quality and high-efficiency in soybean production.【Method】Field experiments were conducted with soybean Kangxian 6. We sprayed growth promoter regulator 2-N,N-diethylamino ethyl caproate(DTA-6) 60 mg·L^-1 and the retardant regulator uniconazole(S3307) 50 mg·L^-1 or water during R1 growth stage in 2012 and 2013. The pods of each treatment were used to examine pod physiological indicators including soluble sugar, sucrose, starch, MDA, POD and AC on 35, 42, 49 and 56 days after spraying in each treatment. Abscission zone tissues between stem and soybean pods were cut on the 5th day after treatment, to determinate the expression of cellulose enzyme gene(Gm AC) using applied RT-PCR method. 【Result】(1) Compared with the control, DTA-6 and S3307 treatments had significantly lower soluble sugar, except on 35 d after spraying where the DTA-6 treatment sugar content was higher. The content of sucrose in pods decreased after spraying DTA-6 and S3307 from the 35 d to the 49 d, and increased on the 56 d after spraying. Starch increased in most of treatment-spray time conditions except in the S3307 treatment on the 42 d after spraying.(2) The content of MDA decreased after 35, 49 and 56 d after spraying. The activity of POD increased after 35 d, 42 d and 56 d after spraying. The activity of AC decreased on the 35 d, 49 d and 56 d after spraying S3307 and decreased from 42 d to 49 d after spraying DTA-6.(3) The relative expression of Gm AC in