从携带S5n基因的水稻种质中发掘San、Sbn和Scn基因

花粉不育是籼粳杂种F₁优势利用的主要障碍之一。包括S_a、S_b和S_c等至少6个基因座位内的等位基因互作会引起花粉不育,这些座位上的中性等位基因可以克服不育性。所以,发掘和利用中性等位基因具有重要意义。本文用携带S₅ⁿ的水稻种质,分别与台中65及其携带花粉不育基因的一套近等基因系杂交,组配具有单个座位互作和多个座位同时互作的杂种F₁,首先通过观察杂种F₁的花粉育性并比较相应杂种F₁育性的差异,初步判断是否具有中性等位基因,然后,采用与S_a、S_b和S_c座位紧密连锁的分子标记对F₂植株基因型的分离进行检测,并分析其分离比例的符合度,确定存在中性等位基因的真实性。结果发现在所鉴定的6份材料中有2份(灰背子和Madhukar)同时携带S_aⁿ和S_bⁿ,3份(饭毫皮、秕五升和粤泰B)携带S_bⁿ,1份(Jackson)携带S_cⁿ。这些材料同时携带可克服杂种F₁胚囊不育和花粉不育的基因,是克服籼粳杂种F₁不育性的重要基因来源。     

萍乡核不育水稻的新恢复系及遗传分析

在构建萍乡核不育水稻显性核不育基因定位群体时,我们意外发现一些前人报道的保持系表现出恢复性,为此本试验对这几个品系与萍乡核不育水稻杂交后代育性分离做了系统的分析。结果表明,萍乡核不育水稻不育单株与可育单株杂交F₁代的不育株与可育株按1∶1分离,高温自交后代不育株与可育株按3∶1分离。萍乡核不育水稻不育单株分别与桂99、特青和9311BB23杂交,它们的F₁代均可育,表现恢复性。由F₁代产生的F_1:2家系中出现全可育群体和育性分离群体的比例为1∶1。其中育性分离群体中不育株与可育株按3∶13进行分离。从育性分离的F_1:2家系中的可育株自交产生的F_2:3家系出现全可育群体和育性分离群体的比例为7∶6。这些分离规律表明,桂99、特青和9311BB23具有恢复基因,并对萍乡核不育水稻的显性核不育基因表现出显性上位作用,能抑制显性不育基因的表达,从而使不育性转变为可育。     

水稻籼粳杂种IR36/Kamairazu花粉育性的遗传

检测了47个水稻籼粳杂种F₁的花粉育性，平均值为(79.9±31.2)%，其中68%组合的花粉育性低于90%。研究了代表性组合IR36/Kamairazu不同世代的花粉育性，F1的花粉育性为79.5%，其衍生的63个F₂单株的平均花粉育性为(91.0±15.7)%。花粉育性高达98.3%的F₂单株A4-3衍生的81个F₃单株的平均花粉育性为(95.9±11.1)%，而育性为61%的A4-6衍生的51个F₃单株的平均花粉育性仅为(74.3±35.2)%。在A4-3衍生的F₃中选用2个花粉育性分别为99.2%和99.5%的单株，其衍生的F4群体的平均花粉育性分别为(93.0±7.4)%和(94.9±3.5)%，而2个花粉育性均为69.2%的单株衍生的F4群体的平均花粉育性则分别为(88.5±22.1)%和(89.8±6.7)%。IR36/Kamairazu的花粉育性受多基因控制，符合多基因座单位点孢子体—配子体互作模式。在F₂、F₃和F₄群体中，平均育性水平较高的群体，单株花粉育性与小穗受精率无显著相关性，而在平均育性水平较低的群体中，花粉育性与小穗受精率呈显著或极显著正相关。     

两个杂交棉F1、F2代及亲本冠层结构与物质生产特征

以杂交棉石杂2号和新陆早43的F₁、F₂代及亲本NT2、H2、4-14为试材,通过测定不同生育时期各材料叶面积指数(LAI)、叶倾角(MTA)、冠层光截获率等指标,分析了各指标变化对群体光合物质生产的影响。结果表明,2个杂交棉F₁代LAI具有超亲优势,冠层光截获率具有中亲优势; LAI和冠层光截获率具有明显的母系遗传特性,而MTA受到父本的显著影响。F₂代冠层结构主要受F₁代相关指标和衰退率的影响,LAI中亲优势减小了衰退率; 杂交棉F₁代光合物质积累主要受亲本参数和超亲优势的影响,F₂代主要受F₁代参数的影响。杂交棉光合物质积累最大增长速率和直线增长期开始时间较晚,直线增长期及活跃增长期较长,最终积累量和最大增长速率较高。杂交棉F₁代具有明显的光合生产和产量优势,F₂代具有一定的产量优势。以选择具有优化冠层结构的亲本为基础,组配具有较大MTA的父本和较大LAI的母本,有利于改善杂交棉光合性能,提高群体光能利用率,进一步挖掘产量潜力,为杂交棉高光效组合的选育及提高F₂代应用提供理论依据。     

水稻野败胞质低温敏两用系新种质的初步研究

水稻低温敏两用系新资源３６３Ｓ是从三系杂交稻威优６３Ｆ２代分离群体中筛选培育的,具有野败不育胞质。在２４℃以下低温诱导表现稳定不育,２６℃以上高温诱导可育,这两种温度条件下其花粉育性与小穗育性表现一致;在２４～２６℃范围内,随温度升高,可染花粉增加,但小穗仍表现败育;短日处理有提高结实率的作用;恢保关系与目前使用的野败类型三系不育系基本一致。该不育基因可能与农垦５８Ｓ系统的光温敏不育基因不等位。     

甘蓝型油菜NCa CMS育性相关候选线粒体基因及其受恢复基因的转录调控

用10个线粒体基因为探针, 对NCa不育系、保持系和可育F₁幼蕾的线粒体RNA进行了Northern检测。结果表明，atp6、atp1、cox1、cox2、cob、rrn5S和rrn26S等7个线粒体基因探针在不育系、保持系、可育F₁中的转录没有差异；只有orf222、orf139和atp9等3个探针检测到转录本的差异。orf222和orf139分别在不育系和可育F1中产生相同大小和丰度的转录本，但是在保持系中没有检测到转录本；orf222检测到的3条转录本分别为1.1、0.9和0.6 kb，orf139检测到0.8和0.6 kb 2条带。atp9探针在不育系和保持系中都检测到1条0.6 kb转录本，而在可育F₁中检测到0.6和1.2 kb的转录本。NCa CMS不育的形成可能与orf222、orf139和atp9基因的表达有关；讨论了恢复基因在F₁育性恢复过程中对育性相关候选基因的可能调控方式。     

转codA基因提高番茄植株的耐热性

以野生型番茄(cv. Moneymaker)和转codA番茄为材料,用不同温度(25、30、35、40、45和50℃)分别处理2 h,测定叶片净光合速率(P_n)、PSII最大光化学效率(F_v/F_m)、过氧化氢(H₂O₂)含量、丙二醛(MDA)含量、相对电导率(REC)和抗氧化酶活性等生理指标;42℃高温处理0、3和6 h后,检测热响应基因的表达量以及D1蛋白的含量,研究高温胁迫对上述参数的影响,探讨转codA基因提高番茄叶片耐热性的机制。。结果表明,高温胁迫下,转codA基因番茄叶片P_n和F_v/F_m的抑制程度明显低于野生型,H₂O₂、MDA的积累量以及REC均低于野生型,而且明显增强了过氧化氢酶(CAT)、超氧化物歧化酶(SOD)、过氧化物酶(POD)和抗坏血酸过氧化物酶(APX)的活性。此外,转codA基因番茄叶片中抗氧化酶基因和热胁迫基因的表达水平均高于野生型,而D1蛋白的降解水平低于野生型。转codA基因番茄体内合成的甜菜碱提高了转基因番茄的耐热性,这与提高和维持较高的抗氧化酶活性、促进热激响应基因的表达及减缓D1蛋白的降解等有关。     

光温敏核不育系Y58S群体育性转换临界温度的提纯研究

本研究选用光温敏核不育系Y58S生产用良种为材料,通过光温敏、温敏核不育水稻的繁殖和鉴定装置进行人工控温低温筛选。研究表明,群体中单株间育性转换的临界温度存在明显分离,随着筛选温度的降低和胁迫时间的延长,群体中仍保持稳定不育的单株减少,而育性恢复正常的单株急剧上升,说明群体中单株间对低温胁迫的耐受能力也存在差异。通过人工低温胁迫筛选可以有效地降低光温敏核不育系育性转换的临界温度和提高育性稳定性。     

低温胁迫下聚糖萘合剂对玉米幼苗光合作用和抗氧化酶活性的影响

采用盆栽试验, 以郑单958和丰单3号为材料, 研究了低温胁迫对玉米幼苗光合作用、叶绿素、叶绿素荧光参数和抗氧化酶活性的影响, 以及聚糠萘合剂(PKN)的调控效果。结果表明, 低温胁迫下, 玉米幼苗的光合作用和光系统II光化学最大效率受到抑制; 超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性降低; 过氧化氢、超氧阴离子的产生速率及丙二醛(MDA)含量显著升高。PKN处理提高了低温胁迫下玉米幼苗净光合速率(P_n)、气孔导度(G_s)、光系统II光化学的最大效率(F_v/F_m)、叶绿素含量(Chl a+Chl b)。低温处理7 d, ZDTR和FDTR的P_n、G_s、F_v/F_m、Chl a+Chl b分别比各自的对照提高了88.95%和61.11%、593.33%和1 741.67%、111.50%和145.16%、36.61%和54.03%; PKN处理延缓了SOD、POD、CAT活性的降低, 低温胁迫7 d, PKN处理使郑单958和丰单3的SOD、POD、CAT活性分别比对照高了292.59%和632.98%、295.07%和360.54%、254.55%和265.45%; 同时降低了过氧化氢、超氧阴离子的产生速率及MDA的含量。表明PKN处理有利于提高玉米幼苗的抗冷性。     

同核异质滇I型粳稻不育系及其保持系的光合特性

滇I型不育系和保持系是我国粳稻杂种优势利用最主要的技术体系之一。本研究利用Li-6400便携式光合测定系统测定了79对滇I型同核异质粳稻不育系及保持系上三叶的净光合速率(P_n)、气孔导度(G_s)、胞间CO₂ 浓度(C_i)、蒸腾速率(T_r)、水分利用效率(WUE)、气孔限制值(L_s)和叶绿素相对含量(SPAD)。结果表明,不育系间及保持系间的光合参数在3个叶位上都达到了极显著水平,基因型间的这种显著差异为高光效育种提供了宝贵的遗传基础。同一叶位上不育系与保持系间的光合参数具有显著的正相关。除SPAD值外,其他光合参数值在不育系与保持系间没有显著差异,但不育系的SPAD值显著大于保持系。叶绿素相对含量不是粳稻提高光合作用的限制因子;滇I型细胞质对光合作用没有负效应;利用滇I型细胞质转育的不育系的叶绿素含量很可能有所提高。基于剑叶光合参数值对保持系及不育系的聚类,不育系和保持系可分别分为高和较低光合速率的类型。本研究为滇I型不育系的高光效育种提供了理论基础,也可作为杂交粳稻高光效的理论参考。     

细胞质雄性不育陆地棉的细胞质效应

哈克尼西棉细胞质与陆地棉核互作不但引起花粉母细胞的败育，而且也影响到胚囊育性，具体表现与保持系比较，不育系的胚珠显著变小，不孕籽率显著变高和异常胚囊的增多，不育系不杂交，Ｆ１的花粉育性接种正常，但自交结铃率仍较低，表明哈克尼西棉不育细胞地对Ｆ１的育怀有一定程度的负效应。然而，这种负效应可以通过优良不育系和强恢复系的选与得以克服或减轻到不显著水平，在强优势组合（Ｆ１）中不育细胞质的负效应，不足以Ｆ１     

New insights into genotypic thermodependency of cytoplasmic male sterility for hybrid barley breeding

The cytoplasmic male sterility (CMS) system msm1 in barley is known to be thermosensitive, sometimes resulting in spontaneous fertility restoration in the absence of the corresponding restorer gene Rfm1. Here, we investigated genotypic differences concerning temperature sensitivity and the plant developmental stage at which elevated temperature induces spontaneous fertility restoration in three CMS mother lines. While one line stayed completely male sterile, a significantly higher fertility was observed in two lines after treatment from growth stage DC 41 until maturation. Microscopic analysis revealed that sterile anthers contained neither intact pollen, nor remains of aborted pollen grains, whereas pollen was visible in anthers of potentially fertile plants. We conclude that the barley CMS system affects anther and pollen development prior to meiosis. Elevated temperature during heading and flowering can lead to a spontaneous fertility restoration by reactivating pollen growth. Nevertheless, genotypic variation exists enabling the selection for stable CMS mother lines and the development of F₁ hybrids with high hybridity. As spontaneous fertility restoration due to environmental effects is difficult to phenotype, further investigations will focus on the development of molecular markers for marker‐assisted selection.     

我国水稻常用保持系穗期耐旱性测评及育性分析

以负压式土壤湿度计和取土烘干法双重监控盆栽试验的土壤水势变化,观测我国15个常用水稻保持系的穗期耐旱性和育性特征。结果表明,K22-B、金23-B及II-32-B等保持系为穗期干旱胁迫钝感材料,而珍汕97-B、中9-B及协青早-B等为穗期干旱胁迫敏感材料;参试保持系在开花期(花粉粒充实期到小穗灌浆初期)比孕穗期(花粉母细胞分裂期到花粉粒充实期,15 d)对干旱胁迫更敏感;保持系孕穗期干旱胁迫主要伤害颖花育性,其胁迫指数与空壳率正相关(r = 0.6988^**), 开花期干旱胁迫不仅伤害颖花育性并影响小穗充实,其胁迫指数与空壳率正相关(r = 0.7660^**),也与秕谷率正相关(r = 0.5230);穗期耐旱性与其正常生育条件下的穗部结实性状不具直接相关性。     

濒危植物珊瑚菜花粉生活力的测定

采用花粉离体萌发法,对珊瑚菜的花粉进行了生活力测定。结果表明:珊瑚菜初花期的花粉萌发率最高,为89.7%;在恒温25℃条件下,以0.6%琼脂+10%蔗糖+0.1%硼酸为离体培养基进行培养,有利于珊瑚菜花粉的萌发;低温（4℃）条件可延长珊瑚菜花粉的寿命,将其进行短期贮藏。     

粳稻恢复系宁恢3-2育性恢复力的遗传

两套粳稻雄性不育系(A)及其保持系(B)分别与宁恢3-2(R)杂交、回交、自交、获得两个组合的 F_1(A/R)、B_2(A//A/R)、B_2′(A//B/R)、F_2和 F_3,以花粉育性和种子育性作为恢复度指标,研究宁恢3-2育性恢复力的遗传。 结果表明,BT 六千辛 A 和 L 平壤3号 A的花粉以染败为主,在光学显微镜下不易区分分离世代植株中可育和不育花粉,     

壁蜂与蜜蜂对棉花胞质雄性不育系的传粉特性比较

为了筛选适用于棉花胞质雄性不育系授粉的蜂种,2013―2014年以蜜蜂为对照,在网室内进行壁蜂对棉花胞质雄性不育系授粉试验,观察壁蜂和蜜蜂在棉花花朵上的生物学特性,并进行田间性状的统计分析。结果表明:壁蜂的适应性较好,受天气影响较小,但温度超过35℃后访花活动明显减少;壁蜂在不育系和保持系上的单花停留时间极显著大于蜜蜂。壁蜂授粉与蜜蜂授粉,在单株结铃数、单铃籽粒数和衣分上差异极显著,单株果枝数、铃重差异显著。蜜蜂授粉较壁蜂授粉平均制种产量高,但壁蜂制种成本低。改进田间管理措施以及采用多次适时释放壁蜂的方式,壁蜂授粉将会在棉花胞质雄性不育系授粉中发挥更大作用。     

乙烯与水稻细胞质雄性不育的关系

从幼穗发育的IV到VII期,水稻细胞质雄性不育系(珍汕97A)幼穗和叶片的ACC含量和乙烯释放速率均高于其保持系(珍汕97B)。外施乙烯释放剂乙烯利使保持系花粉可育度明显下降;外施ACC合成酶抑制剂AVG引起两系幼穗ACC含量和乙烯释放速率下降,并使不育系花粉育性得以部分恢复,而在外施AVG的同时再施以乙烯利则AVG的恢复作用消失。     

The effects of high-temperature stress on the germination of pollen grains of upland cotton during square development

The reproductive stage of flowering plants is sensitive to high-temperature stresses. High temperature is a major factor influencing pollen grain viability in upland cotton (Gossypium hirsutum). The objective of this study was to identify the relationship between cotton pollen germination percentage and temperature by assaying the pollen germination of four upland cotton cultivars in vitro at different temperatures during the blooming period. The results showed that in vitro pollen germination percentage was related to the culture temperature of pollen germination and the temperature of the square development process. High temperature affected pollen development and germination, and high-temperature tolerance differed among the cotton cultivars. The pollen germination percentage decreased rapidly with changes in the culture temperature from 30 to 39 °C. A culture temperature of 35 °C might be a critical temperature for the pollen viability transition and could be used to screen cotton cultivars that have pollen grains with high-temperature resistance. Before the high-temperature stage, cultivars with rates of decrease in the percentage of pollen germination of less than 41 % at 35 °C relative to the rates at 30 °C might be considered as high-temperature tolerance cultivars, and cultivars with rates of decrease in the percentage of pollen germination greater than 41 % might be considered as susceptible cultivars. The high-temperature stress for pollen grain germination in vitro was greater than 30 °C, and the high-temperature stress for square development might be greater than 33 °C. Boll retention was significant; it was positively correlated with the pollen germination percentage and negatively correlated with temperature during the high-temperature stage. This study provided a method for rapidly screening cultivars (lines) with high-temperature tolerance pollen in upland cotton breeding.     

A comparison of cytoplasmic and chemically-induced male sterility systems for hybrid seed production in wheat (Triticum aestivum L.)

A comparison of two male sterility systems was carried out in wheat for hybrid seed production and hybrid performance. Seventeen hybrid combinations based on Triticum timopheevi cytoplasm were compared with their genetically equivalent CHA-facilitated combinations. The same set of restorer lines was used as parents in CMS- and CHA-based hybrids to maintain genetic equivalence. In the first experiment aimed at study of female line behavior and crossed seed production, the CHA treated lines showed significantly shorter heights whereas CMS lines were similar to the control. The two systems were equally effective in sterilizing rate. The outcrossing percentage of the CMS lines was almost twice that of the CHA treated lines. Thousand-grain weight of the crossed seeds on CMS lines was greater than on the CHA treated lines and control. On average, the germination percentage of seeds on CMS lines was double that of the CHA treated lines and the percentage of effective outcrossed seeds in CMS lines was 3 times more than that from CHA treated lines. The second experiment was conducted to examine the yield performance of the hybrids derived from the two systems of male sterility. A total of 40 entries including 20 hybrids and 20 parents were evaluated in the experiment. The mean grain yield of the CMS-based hybrids was greater than that of the CHA-based hybrids,the B and R lines. All the CMS-based hybrids showed significantly higher grain yields than their better parents whereas all the CHA-based hybrids, except two,showed no significant yield increases over their better parents. Possible reasons for differences in CMS- and CHA-based hybrid performance are discussed. This revised version was published online in July 2006 with corrections to the Cover Date.     

Meiosis and Pollen Viability in Helianthus tuberosus L. and its Hybrids with Cultivated Sunflower

The hexaploid species of Helianthus tuberosus is a potential source of resistance to several sunflower pathogens. But crossed with cultivated sunflower, it produces F, hybrids which have low values of fertility or even full sterility. Pollen viability and meiotic features were studied in 17 populations of the species H. tuberosus and in F¹ hybrids. Significant differences in pollen viability existed between populations (47.1–98.8%). In the 15 FI hybrids, plant fertility ranged from 0 to 100 per combination, while pollen viability ranged from 12.4 to 57.1. Meiosis was almost normal in the analyzed species, and irregular in the F, hybrids. The highest percentage of meiocytes was with bivalents (85.9), but univalents (0.3) and multivalents (13.8) occurred as well. In metaphase and anaphase, the percentage of meiocytes with fast and lagging chromosomes was high. In anaphase, chromosome bridges were detected in 9.9 of the meiocytes.