Rht12矮秆基因在不育系繁殖中的应用研究

Utilization of Rht12 Dwarfing Gene in Seed Production of Male Sterile Line

为了解决小麦矮秆不育系的繁殖问题 ,使半矮秆杂种小麦尽快投入生产应用 ,利用中国农业大学从德国引入的 Rht1 2矮秆系与江苏省小麦推广品种杂交和回交 ,育成了适合江苏省南部种植的Rht1 2矮秆系及其 T型细胞质雄性不育系。由同一品种转育的 Rht1 2矮秆系 ,其株高变动于 50～ 90 cm之间 ;不同株高的 Rht1 2矮秆系可以配制出不同株高的杂种 F1。在拔节期至孕穗期喷施 50～ 1 0 0 mg/ kg的赤霉酸溶液 ,可以使 Rht1 2矮秆系的株高显著增加。在不育系种子繁殖区内 ,喷施 50 mg/ kg的赤霉酸溶液 ,保持系株高由 65cm增加到 90 cm,不育系植株的异交结实率由对照的 2 0 .2 %增加到 60 .4 % ,从而显著地提高了不育系种子产量。株高的差异也能在收获时防止保持系种子混入不育系中 ,从而可以确保不育系种子的纯度。本文还讨论了如何解决 Rht1

Prospect of Rht12 dwarfing gene used in hybrid wheat was evaluated in this paper. Low yielding of male sterile line seed production still remained a big problem to hinder the commercialization of semi-dwarfing hybrid wheat with Rht3 gene. Wheat plant carrying Rht12 gene was sensitive to exterior GA3. It was possible to condition plant height in field by GA3 treatment. Exploitation of Rht12 in hybrid wheat could facilitate the production of male sterile line seed and result in a higher seed yield. In our breeding scheme, an original Rht12 dwarfing line introduced from China Agricultural University had been crossed and backcrossed with local varieties of Jiangsu province. Preliminary results showed that: the selected Rht12 dwarfing lines displayed good adaptability to the habitat of southern Jiangsu province. Some of these lines were developed into male sterile lines with T. timopheevii cytoplasm subsequently. The plant height of the Rht12 dwarfing lines derived from the same variety differed and ranged from 50 cm to 90 cm. Hybrid F 1s with different plant height might be bred out with the Rht12 dwarfing lines with different plant height. Spraying of 50~100 mg/kg GA3 solution between jointing stage and booting stage could promote plant height of Rht12 dwarfing lines significantly. In a male sterile line seed production trial, the plant height of maintainer sprayed with 50 mg/kg GA3 solution increased from 65 cm to 90 cm. The outcrossed seed set rate of male sterile line went up to 60.4% while that of the control was only 20.2%. Thus a notably higher yield of male sterile line could be obtained. Moreover, the difference of plant height could prevent mingling of maintainer seed and ensure the purity of male sterile line seed. How to solve the problem of late maturity and leaf senescence of Rht12 dwarfing line was also discussed in this paper.