光敏感核不育水稻育性诱导和转换过程中叶片内碳水化合物的变化

本文以光敏感核不育水稻农垦58-s 和常规水稻农垦58为材料,从第一次枝梗原基分化后期至花粉母细胞形成期用不同光周期(SD 和 LD)进行育性诱导处理,半微量的二硝基水扬酸法定糖结果表明:1.从第一次枝梗原基分化至雌雄蕊形成期,农垦58(SD~(**)或 LD~(***))的淀粉含量逐渐增加,蔗糖和还原糖含量经过一个相对稳定的阶段(Ⅱ—Ⅲ)后,迅速增加,至雌雄蕊形成期时,淀粉、蔗糖和还原糖含量达到高峰,随后逐渐下降。2.从第一次枝梗原基分化至雌雄蕊形成期,农垦58-s(SD 或 LD)的淀粉、蔗糖和还原糖含量的变化规律与农垦58一致。但是,在雌雄蕊形成期之后,农垦58-sSD~(****)的蔗糖含量下降,淀粉和还原糖含量缓慢增加,而农垦58-sLD~(*****)的淀粉、蔗糖和还原糖含量均明显增加。推测长日照可能通过某些代谢环节影响了农垦58-s 叶片内碳水化合物向雄蕊的运输。营养缺乏是造成小饱子败育的重要原因之一。     

粳稻品种中掩盖光敏核不育性的主效恢复基因分析

1989—1991年分析了农垦58、农垦58s(R)和1149分别与农垦58s杂交及其相互杂交的F_1、F_2和BCF_1群体在武汉(30°30′N)自然长光照条件下的育性表现。其中,农垦58s是从农垦58群体中突变产生,农垦58s(R)是从农垦58s群体中突变后育成的稳定可育品系,1149是从农垦58s与粳稻品种农虎26杂交F_2中的低可育株选至F_10的稳定可育品系。试验结果表明,在供试粳稻品种或品系中,共有两个独立遗传的显性主效恢复基因,与以前的研究结果互相印证;但农垦58s(R)可能不是农垦58s原位回复突变产生,而是农垦58s另一对隐性主效基因突变所致。农垦58s光敏核不育的主基因型标示为m~(ph)m~(ph)r_f~(ph)r_f~(ph),农垦58、农垦58s(R)和1149的主基因型相应标示为m~(ph)m~(ph)r_f~(ph)r_f~(ph)、m~(ph)m~(ph)R_f~(ph1)R_f~(ph1)和m~(ph)m~(ph)R_f~(ph2)R_f~(ph2),M~(pn)与R_f~(ph1)或R_f~(ph2)为非等位基因,R_f~(ph1)和R_f~(ph2)为复等位基因。M~(ph)表现为完全显性,其表现型为可育;R_f~(ph1)和R_f~(ph2)均表现为不完全显性,其表现型为部分可育,但两者育性恢复能力存在明显差异。本文还对农垦58s与农垦58s(R)正、反交F_1育性很低的试验结果进行了讨论。     

Photoperiod sensitivity in three rice crosses

Summary The degree of photoperiod sensitivity was studied in the F₅ and F₆ of three crosses between sensitive and insensitive rice cultivars under field conditions. Photoperiod sensitive lines could be identified as nonflowering lines in a February-seeded nursery. These lines had a short critical daylength (i.e. late flowering date). The strongly sensitive lines also had a high degree of photoperiod sensitivity, measured as the ratio of the difference in growth duration for two seeding dates to the difference in seeding dates in the main wet season. Some lines, however, with a relatively high degree of sensitivity and a longer critical daylength, were able to flower in the February-seeded nursery. In the cross KDML 105 × IR42, photoperiod sensitivity showed a bimodal distribution, suggesting major gene control. In Latisail × IR28 and KDML 105 × IR50, the inheritance was not clear. In KDML 105 × IR42, 37 out of 97 F₅ lines were strongly sensitive and in KDML 105 × IR50, 7 out of 95 F₅ lines were strongly sensitive. Thus the choice of the insensitive parent greatly influenced the number of strongly sensitive lines recovered. Degree of photoperiod sensitivity was positively correlated with plant height in the wet season. In the dry season this was not observed, because the sensitive lines flowered earlier.     

Response of pepper and eggplant to continuous light in relation to leaf chlorosis and activities of antioxidative enzymes

Activities of the oxygen radical-scavenging enzymes were determined in leaves of ‘Kyomidori’ pepper (Capsicum annuum L.) and ‘Senryo’ eggplant (Solanum melongena L.) seedlings under two photoperiod treatments; 12 h light/12 h dark (12/12 h) or with continuous light (24/0 h) for six days. Growing eggplant under continuous light resulted in leaf chlorosis after four days and a sharp decline in the chlorophyll content. In eggplants grown under 24/0 h photoperiod, the activities of antioxidative enzymes; superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) rapidly increased from day two. This was an indication of photooxidative damage. In contrast, leaf chlorosis did not occur in pepper plants grown under continuous light, while the chlorophyll content was even higher in the 24/0 h than in the 12/12 h photoperiod. Continuous light did not enhance the activities of SOD and POD in leaves of pepper. However, the CAT activity increased faster and was significantly higher in pepper than in eggplants grown under continuous illumination. Pepper plants did not appear to suffer from photooxidative damage and thus grew normally under continuous illumination.     

光周期对冬小麦穗分化的影响(Ⅱ)

[目的]进一步了解光周期对小麦穗分化的影响。[方法]以泰山9818、J30等冬小麦品种为材料,采用盆栽方式,于小麦返青后不同时期进行长日照转短日照、短日照转长日照的光周期处理,解剖镜观察小麦分化期的不同。[结果]随着短日照处理后延,短日延迟作用减弱。在前期长日照的基础上,小麦雌雄蕊后短日照延迟作用最小或无。二棱期转短日照后,光周期敏感型品种J30未能抽穗。短日延迟作用有一定的"滞后期"。二棱期短日照转长日照后,各品种的穗分化进程明显加快,J30也能抽穗,再次表现出光周期反应的滞后。光周期不敏感型品种的反应较小。[结论]光周期不敏感型品种受光周期的影响小于光周期敏感型品种。     

光周期对菊花花芽分化和内源激素的影响

本试验以菊花品种"秀芳白"为试材,研究了不同光周期(昼/夜分别为16h/8h,12h/12h和8h/16h)对菊花花芽分化及其过程中内源激素IAA、GA3、CTK和ABA含量的影响。结果表明,16h/8h处理的植株始终没有花芽分化;8h/16h处理的植株从处理到花芽分化开始和花芽分化完成所需天数分别为12.8 d和25.1 d,比12h/12h处理的分别提前2.4 d和4.7 d。花芽分化过程中16h/8h处理的IAA和GA3含量呈现缓慢下降趋势,而8h/16h处理和12h/12h处理的呈现迅速下降趋势;16h/8h处理的CTK和ABA含量没有出现明显变化,而8h/16h处理和12h/12h处理的呈现上升趋势。CTK/IAA、CTK/GA3、ABA/IAA以及ABA/GA3在16h/8h处理区没有明显变化,而在8h/16h处理和12h/12h处理区呈现上升趋势。说明短日照促进菊花花芽分化,而且日照时数越短,花芽分化越快;花芽分化过程中叶片GA3和IAA含量减少,CTK和ABA含量增加,而且CTK/IAA和CTK/GA3以及ABA/IAA和ABA/GA3比值增加,有利于菊花花芽分化和提早开花。     

扁茎大豆的花序形态受光周期的调控研究

以扁茎大豆、正常圆茎大豆、扁茎大豆与正常圆茎大豆杂交选育的高代品系为材料,分别进行短日照(12h)和长日照(16h)处理,观察光周期对扁茎大豆及正常圆茎大豆发育速度和形态特征的影响.结果表明,光周期不仅明显影响大豆的开花期、成熟期,而且调控顶端花序的形态.在长日照下,供试大豆品种生殖发育明显受到抑制,开花期延迟,在北京夏播条件下不能正常成熟;扁茎大豆、扁茎大豆与正常圆茎大豆杂交选育的高代品系植株顶端花序轴伸长,部分材料的花序轴上产生侧生花序,但均未象在原产地一样出现扁平、加宽的花序.在短日照条件下,不论是扁茎大豆还是正常圆茎大豆,发育速度均加快,植株顶端为典型的总状花序,花序轴较短,扁茎大豆也未出现扁茎及顶端花序簇集的现象.本实验的结果说明扁茎大豆植株顶端的茎秆扁化、花荚簇集的性状可因光周期等环境因素的变化而变化,是不稳定的性状.对扁茎性状形成和变化的原因亦进行了分析.     

曙暮光在光敏感核不育水稻两个光周期反应中的作用

 本文论证了曙暮光在光敏感核不育水稻两个光周期反应中均有明显的作用,初步探明农垦58S 在武汉地区(30°27′N)育性转换期(7—8月)曙暮光的变化规律,提出采用“光照长度”以代替“日照长度”来划分光周期的昼与夜更为准确的见解,据此讨论了曙暮光的作用对光敏感核不育水稻在不同地理条件下的生态适应性的重要影响。     

小麦品种对日长反应的研究

采用13个小麦品种于人工控光和广州自然光5级日长下，先后于1985年和1987年年份两年共7期播种，盆栽和田间试验结合，结果表明冬性品种有严生格的出穗临界日长，但日长变化对出穗迟早影响极微；春性和半冬性品种未发现有出穗临界日长，但长日出穗促进率大，春性和半冬性品种出穗的光温联应方程为y=a-b1x1-b2x2，即出穗日数随日长增长温度升高而缩短，但华南春性品种出穗受日长影响大于受温度影响，而四川、 宁夏春性及山东半冬性品种3受温度影响则甚于受日长的影响，冬性品种方程为y=a-b1x1 b2x2，即出穗日数随日长随长而缩短，随温度升高而增加，温度影响较日长影响大，文章还探讨了日长结合温度对小麦生育期、穗粒性状等的作用。     

光敏色素研究进展

综述了自20世纪20年代光敏色素被发现以来的研究概况及进展.主要包括(1)光敏色素作为主要光受体在调节从种子萌发到器官衰老的植物生长过程中所发挥的作用;(2)光敏色素的5种不同基因型及基因同源性和主要的反应方式,尤其是光敏色素的主要分子基因PhyA和PhyB在反应方式上的区别;(3)从生物化学和分子水平阐述了光敏色素的生理功能,其中包括光敏色素对细胞生长的调节,光敏色素是如何通过调节光周期反应进而调节了生长和开花的,光敏色素对基因表达的调控以及光敏色素与植物激素协同作用于植物生长和育性等;(4)虽然迄今为止人们极少研究光敏色素和植物激素在苜蓿秋眠中的作用,但对此方面提出了研究展望.