玉米细胞质雄性不育系的鉴定

采用田间育性调查、花粉活力检测、特异引物PCR鉴定及细胞学形态观察等方法来研究新育成的雄性不育系DT-合344、ZT-合344的育性特点、胞质类型。结果表明,这两个不育系均为T型细胞质败育类型,该研究结果为进一步深入研究不育系的不育分子机理和生产应用奠定基础。     

海洋酸化对海水青鳉性别分化的影响

以海水青鳉作为研究对象,研究海洋酸化对其性别分化的影响。将刚受精的受精卵置于对照组(CO_2浓度为480×10~(-6))和2个处理组(CO_2浓度分别为1 000×10~(-6)和2 000×10~(-6))的水体中,直到孵化出膜。将出膜后仔鱼饲养在对照组水体中至性成熟,然后通过形态学、组织学和遗传学方法,对每一尾实验鱼进行表现型和基因型的性别鉴定。经形态学判断,发现酸化处理组的雄雌比例显著高于对照组(P0.01)。经形态学观察其第二性征和遗传学性别判断,对照组的青鳉从孵化到性成熟的个体中并未出现基因型和表现型性别不一致的个体,而在2个酸化处理组中,均有基因型为XX而表现型为雄性的个体,即性逆转雄性,性逆转率分别为38.4%和47.5%。     

冬春温度变化对小麦温敏雄性不育系BNS的育性转换影响

BNS是一个主体受温度控制的新型小麦雄性不育系,表现为花粉发育在低温下(8℃)不育,高温下(12℃)可育。BNS不育性稳定,但年份间常有波动,一些年份自交结实率上升显著。为了弄清楚BNS育性波动的原因,连续3a观察不同播期的BNS穗分化过程,分析连续6a调查的BNS自交结实率与对应年份的冬春温度变化,结果发现,冬季和春季温度的改变显著影响BNS的自交结实率。一般规律是,暖冬年份自交结实率低,寒冬较高,暖春年份自交结实率高,寒春较低。该现象的形成主要是BNS冬季生长发育速度所致,暖冬年份BNS冬季仍保持生长,到春季时完成温度敏感期前的发育,较早进入温度敏感期,此时的春季温度较低,因此BNS不育;然而在寒冬年份,BNS停止生长,春季需生长一定时间才进入温度敏感期,进入时气温已较高,因此诱导育性转换,自交结实率增高。BNS冬季生长发育速度在穗分化观察中得到验证。该机理解释了不同年份BNS自交结实率的波动,并根据冬春温度可预测BNS的育性转换。     

新疆两种星翅蝗外生殖器的比较研究

对意大利蝗、黑腿星翅蝗两种星翅蝗雄性外生殖器、雌性下生殖板进行比较解剖,并描述其形态特征。结果表明,两种星翅蝗雄性外生殖器变化最为明显的部位是阳具基背片的侧板及阳具复合体的色带基支、色带瓣、阳茎端瓣。两种星翅蝗雌性下生殖板变化最为明显的部位是下生殖板的前突基内支及腹产卵瓣腹基瓣片。外生殖器特征在意大利蝗和黑腿星翅蝗存在明显差异,可作为两种蝗虫区别性状。     

牛磺酸对不同月龄雄性大鼠生殖器官指数及生殖激素水平的影响

通过给不同月龄雄性W istar大鼠饮用添加1%牛磺酸或1%β-丙氨酸(牛磺酸转运抑制剂)的自来水,研究牛磺酸对不同月龄雄性大鼠体重、生殖器官指数及生殖激素分泌水平的影响。结果表明:牛磺酸对不同月龄大鼠体重、睾丸指数、前列腺指数没有明显的影响,但显著提高了14月龄大鼠的精囊腺指数;显著提高不同月龄雄性大鼠的血清睾酮水平(P<0.05),对血清促卵泡生成素(FSH)、促黄体生成素(LH)水平没有显著的影响。     

化学药物GSC不同浓度对白菜型冬油菜主要性状的影响

以白菜型冬油菜品种鉴94为材料,研究化学药物GSC的不同浓度对白菜型冬油菜主要性状的影响。结果表明,GSC处理两次后,导致植株生长势变弱,而对结实力无显著影响;对油菜花冠和花瓣的生长有一定抑制作用,随着化学药物浓度的增加,花冠直径和花瓣面积呈减小趋势,雄蕊长度逐渐缩短,雌蕊无显著变化,T7浓度处理(第一次0.5 mg·L^-1和第二次0.6 mg·L^-1浓度处理)后,花丝萎缩,花药干瘪,出现大量不育花粉。GSC可以诱导白菜型油菜产生雄性不育,随着GSC浓度的增加,不育株数和失活花粉数也逐渐增加,在T7浓度,植株不育株率达86.49%,失活花粉率达89.30%;同时用此浓度处理后花粉囊发育不良,绒毡层细胞提前解体或随花粉粒退化一同消失,小孢子团紧贴内壁,数量变少。试验说明化学药物GSC对白菜型冬油菜具有一定的杀雄效果,同时杀雄效果与药物浓度有一定关系。     

赤眼蜂寄生行为研究（Ⅳ）—子代数量分配和子代性分配

本文在对赤眼蜂性控行为研究的基础上〔3〕,进一步探讨了不同种赤眼蜂在同一种寄主不同分布以及同一蜂种(松毛虫赤眼蜂 Trichogramma dendrolimi)在不同种寄主上的子代数量分配和子代性分配问题。研究结果表明,赤眼蜂具有根据寄主卵体积大小分配及调整其子代数量和子代性别的能力,在不同体积的寄主上具有明显不同的子代数量安排策略和子代性安排策略。在同一种寄主卵上,不同种的赤眼蜂对子代性分配的安排存在着较明显的种间差异.在米蛾卵上,松毛虫赤眼蜂的第一雄卵主要在其第一产卵序产出,稻螟赤眼蜂的第一雄卵主要在其第二产卵序产出,拟澳洲赤眼蜂产第一雄卵的位置比较分散,主要分布在前三卵序。松毛虫赤眼蜂大约每产6粒雌卵而产1粒雄卵;稻螟赤眼蜂和拟澳洲赤眼蜂大约每产5.33和3.37粒雌卵而产1粒雄卵(见表2).寄主卵的体积不同,雌蜂在不同寄主上所分配的子代数量也明显不同。松毛虫赤眼蜂在每粒米蛾卵上只安排1粒蜂卵;在每粒马尾松毛虫卵上平均安排18.64粒蜂卵;在每粒“人造卵”上平均安排33.15粒,在柞蚕卵上平均安排77.43粒蜂卵(见表3)。随着寄主卵体积的增大,雌蜂产第一雄卵的时间后移,在松毛虫卵上,松毛虫赤眼蜂雌蜂在产下第一粒雄卵后,大约以每产16粒雌卵而产1粒雄卵;在柞蚕卵上,大约每隔15粒雌卵产1粒雄卵;在“人造卵”上,产雄卵的间隔大约为9粒雌卵。     

Effect of alien cytoplasm and fertility restorer genes on agronomic and physiological traits of Brassica juncea (L.) Czern

To assess the effect of alien cytoplasm and fertility restorer genes on agronomic and physiological traits in Brassica juncea, cytoplasmic male sterile (CMS) and fertility restorer lines involving five alloplasms in three nuclear backgrounds were constituted through repeated backcrossing. These lines were evaluated along with euplasmic lines for agronomic traits in field experiments. Respiration efficiency of in vitro cultured hypocotyls, and chlorophyll content in leaves were also estimated. Significant adverse effects of trachystoma and catholica cytoplasms on yield‐contributing traits and yield were noticed. The restorer gene corrected the floral defects in CMS trachystoma and restored yield to the level of euplasmic line, while it did so only partly in CMS catholica. Restorer genes had no adverse effect on traits in any of the systems. On the contrary, the Rf gene of moricandia CMS system exerted a positive effect on leaf chlorophyll content. Likewise, in vitro assay indicated the moricandia CMS system as vigorous. The moricandia CMS plants gave higher seed yield perhaps due to overall better vigour and higher leaf chlorophyll content.     

Methodology for creating alloplasmic soybean lines by using Glycine tomentella as a maternal parent

Soybean breeders have not exploited the diversity of the 26 wild perennial species of the subgenus Glycine Willd. that are distantly related to soybean [Glycine max (L.) Merr.] and harbour useful genes. The objective of this study was to develop a methodology for introgressing cytoplasmic and genetic diversity from Glycine tomentella PI 441001 (2n = 78) into cultivated soybean using ‘Dwight’ (2n = 40) as the male parent. Immature seeds (19–21 days post‐pollination) were cultured in vitro to produce F₁ plants (2n = 59). Amphidiploid (2n = 118) plants, induced by colchicine treatment, were vigorous and produced mature pods and seeds after backcrossing with ‘Dwight’. The BC₁ plants (2n = 79) produced mature seeds in crosses with ‘Dwight’. Chromosome numbers in BC₂F₁ plants ranged from 2n = 41–50. From BC₂F₂ to BC₃F₁, the number of plants in parentheses with 2n = 40 (275), 2n = 41 (208), 2n = 42 (80), 2n = 43 (27), 2n = 44 (12) and 2n = 45 (3) were identified. Fertile lines were grown in the field during 2012 and 2013. This is the first report of the successful development of new alloplasmic soybean lines with cytoplasm from G. tomentella.     

Assessment of cytoplasmic effects of cytoplasmic male-sterile lines in upland cotton

Paired A- and B-lines, cytoplasmic male-sterile (CMS)-lines and main-tainer lines, respectively, were crossed with R-lines (restorer) to produce A × R, R × B and B × R hybrids, which were used in 1993 and 1996 to predict the performance of three lypes of CMS cotton lines available in China. A significant difference in yield and yield components was revealed between paired A × R and B × R hybrids. This difference was greatly influenced by both CMS cytoplasm and the interaction between cytoplasm and nuclear genotypes. It is suggested that there are detrimental effects of CMS cytoplasm on yield and yield components. General combining ability of near-isogenic CMS lines was also affected by this negative effect. The detrimental effect was closely related to an increased number of immature seeds per boll, which might be caused by partial female sterility associated with CMS cytoplasm. The possibility of developing specific combinations of CMS Upland × Upland restorer hybrids that express enough heterosis for yield to overcome the detrimental effect of the CMS cytoplasm is discussed.