Differences in Nuclear DNA Between Male-Sterile and Male-Fertile Lines of Sorghum bicolor

Cytoplasmic male sterility(cms)is determined by nuclear-cytoplasmic interactions. Up to now, most studies are focused on the comparison of cytoplasmic DNAs of male-sterile lines and male-fertile lines, and analysis of nuclear DNA has not been documented yet. In order to find out the possible difference in nuclear genome of male-sterile line A1 Tx623 and corresponding male-fertile line Tx623 of sorghum, random amplified polymorphic DNA(RAPD)approach was used to analyze their cytoplasmic and nuclear genomes. Total DNAs of them were amplified at first to screen primers, which were able to generate reproducible bands specific to male-sterile line or male-fertile line. Then the selected primers were used to amplify their mitochon-drial DNA(mtDNA)and chloroplast DNA(cpDNA). The origins of all the polymorphic fragments were analyzed. After ruling out those amplified from cytoplasmic DNA, seventeen polymorphic fragments were determined to be amplified from nuclear DNA. These fragments originated from nuclear DNA indicate that differences in sequence exist between the nuclear DNA of male-sterile line and male-fertile line of sorghum, which do not agree with the traditional standpoint that they have identical nucleus.

Solutions to Insecurity Problems in Seed Production of Two-line Hybrid Rice

The insecure problems of seed production have seriously hampered the healthy and sustainable development of two-line hybrid rice.The safety issues on seed production of two-line hybrid rice and current research situation were pointed out in this paper.The three main reasons for unsafety in seed production of twoline hybrid rice were unsuitable site selection,high critical sterility-inducing temperature and the drift of critical temperature.In this paper,strategies and measures were put forward based on many years of practice.It could minimize the risk in seed production of two-line hybrid rice by selecting dual-purpose genic male sterile line with lower critical sterility-inducing temperature and long lower temperature resistant time.Based on the climate data and climatic demands of the ＂three safe-periods＂ in seed production,a new idea for determining appropriate bases and periods for seed production was proposed by using computer technology,which solved the aimless selection of sites and periods for the seed production of two-line hybrid rice.Besides,we established a system of single plant selection and identification method and original seed propagation with cyclic cold water,which could reduce the generation number of original seed propagation in seed production and avoid the drift of critical sterility-inducing temperature.This paper improved the seed production safety in the three aspects of seed nature,seed source and seed production site.

Thoughts and Practice on Some Problems about Research and Application of Two-Line Hybrid Rice

The main problems about research and application of two-line hybrid rice were reviewed, including the confusing nomenclature and male sterile lines classification, the unclear characteristics of photoperiod and temperature responses and the unsuitable site selection for male sterile line and hybrid dce seed production. In order to efficiently and accurately use dual-purpose genic male sterile lines, four types, including PTGMS （photo-thermo-sensitive genic male sterile rice）, TGMS （thermo-sensitive genic male sterile rice）, reverse PTGMS and reverse TGMS, were proposed. A new idea for explaining the mechanism of sterility in dual-purpose hybrid rice was proposed. The transition from sterile to fertile was involved in the cooperative regulation of major-effect sterile genes and photoperiod and/or temperature sensitive ones. The minor-effect genes with accumulative effect on sterility were important factors that affected the critical temperature of sterility transfer. In order to make better use of dual-purpose lines, the characterization of responses to photoperiod and temperature of PTGMS should be made and the identification method for the characterization of photoperiod and temperature responses of PTGMS should also be put forward. The optimal ecological site for seed production could be determined according to the historical climate data and the requirements for the meteorological conditions during the different periods of seed production.

朝天椒新品种‘石辣6号’的选育

‘石辣6号’是以辣椒核质互作型雄性不育系T108A为母本,恢复系Q1-352C231为父本杂交配制而成的朝天椒一代杂交种。中熟,平均始花节位14.5节,播种到红熟131 d。单株挂果210个左右,单果质量4.6 g左右。果实小羊角形,果面微皱,果纵径9 cm,果横径1.3 cm,果肉厚1.4 mm,平均制干率27.81%。辣椒素总含量1.33 g/kg,辣度2.05万SHU。在西南地区一般每667 m^(2)产鲜红椒1 500 kg左右,田间表现高抗疫病、抗病毒病、高抗细菌性叶斑病。该品种为鲜食加工兼用型品种,加工品质好,适宜在西南地区海拔高度500~1 500 m及相似区域作春夏露地及早春地膜覆盖种植。

棉花核雄性不育系的培育与利用研究进展

为促进棉花核雄性不育杂交种在在生产上大面积应用,对棉花核雄性不育系的类型、培育与利用、杂交种生产方法等进行了综述。介绍17种棉花核雄性不育系的基因类型及其不育性遗传,通过采用自然突变体的选择、人工诱变、人工转育和改良、生物技术创造等方法培育核雄性不育系,应用于棉花育种研究,中国选育出利用ms14和ms5ms6的核雄性不育杂交种28个,杂交制种技术方法和标记不育系的研究进展为高效简化的杂交制种技术提供支撑。分析指出棉花核雄性不育系的应用前景较好,提出核雄性不育杂交种扩大应用的技术关键是要在标记不育系的研究和创造方面取得突破,在当前核不育杂交种制种中采取不拔除可育株、标记后人工辅助去雄可节约制种用工而不降低制种产量。

陆地棉双隐性核雄性不育系ms_5ms_6花药发育过程的研究

利用石蜡切片技术从胚胎学方面对其进行研究,发现陆地棉双隐性核雄性不育系ms5ms6花药的败育时期是在花粉母细胞时期和小孢子发育期,以小孢子发育异常为主。败育特征为:花粉母细胞时期有少量核仁穿壁现象,还有部分小孢子母细胞出现半月形。小孢子时期出现小孢子粘连和少量的五分体,小孢子都没有刺突长出,最后解体、退化。不育花药和可育花药的绒毡层无明显差异,但不育花药的绒毡层分泌胼胝质的功能不正常。

解决低温敏两系核不育系繁殖问题的策略与实践

为了解决低温敏两系核不育系繁殖中存在的问题,根据云南保山市48年(1953—2000年)的气象资料统计和云南保山市不同年份、不同基地、不同不育系繁殖试验。结果表明,云南保山市不育起点温度为22℃的两用核不育系育性敏感期和抽穗杨花期同时满足的概率为83.34%,比海南三亚市高出48.34%;不同不育系在云南保山市繁殖时育性转换顺利,特别是C815S在海拔1560m的基地大面积繁殖,产量达9133.5kg/hm2,提出了解决低温敏两系核不育系繁殖问题的策略是建立云南保山市两用核不育系繁殖基地。

棉花洞A型核雄性不育完全保持系M_B在不同地区气候条件下育性变化研究

四川省棉花研究所１９８７年育成棉花洞Ａ型核雄性不育完全保持系ＭＢ。在四川简阳地区的气候条件下，ＭＢ自身散粉指数达７６％左右，与洞Ａ不育株杂交，获得不育株和株不育度均达１００％的ＭＡ不育系，ＭＡ不育系可作为配制杂交棉的母本。在武汉市的气候条件下种植，ＭＢ雄性可育性基本丧失，表现近似ＭＡ。ＭＢ的花粉母细胞减数分裂和小孢子发育的单核期，如日平均气温为２４～２７℃，相对湿度在８０％以上时对发育有利，可产生较多的可育小孢子，如温度超过２７℃，相对湿度在８０％以下时则不利，产生大量的不育小孢子。在棉花现蕾开花的主要季节６月中旬至９月中旬，一般情况下，武汉市的日平均气温比简阳高２℃左右，６月下旬已达２８℃，７月下旬比简阳高７℃左右，对小孢子发育不利；这期间武汉市的相对湿度变动在７０％～９５％之间，而简阳稳定在８０％左右。在两气象因子中，日平均气温对小孢子母细胞和小孢子单核期发育的影响比相对湿度更大些。

甘兰型双低油菜细胞核雄性不育系黔油2AB育性遗传研究

根据遗传学原理 ,采用测交、回交、自交及兄妹交的方法 ,研究黔油 2 A的育性遗传规律。结果表明 :黔油 2 A属双基因显性“杂合两型系”,其育性是受两对显性基因 Ms Ms和 Rf Rf互作控制的 ,其中 Ms是显性不育基因 ,Rf是显性恢复基因 ,同时抑制不育基因性的表达 ,使育性恢复可育。其不育株基因型为 Msmsrfrf,保持株基因型为 msmsrfrf,恢复株基因型Ms- Rf Rf和 msm Rf

甘蓝型油菜雄性不育恢复系的筛选

对157份优质和常规油菜品种的测交筛选表明,恢复基因较多地分布于优质品种中,而不育基因则较易在常规品种中发现。因此,恢复系的筛选和选育主要应在当前国内外培育的优质品种中进行。本研究从优质品种中选育出一批恢复性能较好的恢复系,其中有些恢复系具有异质多恢性,从而为加快选育优质杂交油菜提供了有价值的材料。

广东优质两用核不育系的选育策略及利用评价

根据广东省的具体情况 ,初步确定广东实用型两用核不育系的光温不育类型以温敏型为主 ,适当兼顾光温互作型 ,不育起点温度 2 2～ 2 3℃。介绍了不同熟期两用优质核不育系的选育策略 ,以及GD 8S、安农S 1/浙92 4 8等几个新育成的优质两用核不育系的生产利用前景。

芝麻雄性核不育系氨基酸含量变化初探

在芝麻盛花中期,比较分析芝麻雄性核不育系中不育株与可育株不同发育时期的花蕾和叶片中各种氨基酸的含量差异。同可育株相比,不育株不同时期花蕾中天冬酰胺、脯氨酸、谷氨酸、赖氨酸、亮氨酸的差异较为明显,这些物质代谢的变化可能与芝麻雄性不育有关。不育株叶片中各种氨基酸略有不同,但总量差异不太明显。

白菜核不育两用系与玻里马胞质不育系及其保持系的性状比较分析

用比较分析的方法 ,对白菜核不育两用系与玻里马胞质不育系及其保持系的植株性状、育性、花器结构和花粉扫描电镜形态等进行观察研究。结果表明 ,玻里马不育系及其保持系的生长势强于核不育两用系 ,其中不育株的生长势强于可育株 ,且分枝数也较可育株多。两用系不育株的花蕾松软 ,花朵花冠较小 ,花丝短缩 ,花药戟形、褐色无粉 ,花粉粒空瘪畸形。玻里马不育系花蕾瘦瘪 ,花瓣皱缩 ,花色较淡 ,花粉粒多瘦瘪。两用系不育株花粉败育比玻里马不育系要明显 ,而花药败育则相反。两用系可育株与玻里马保持系花粉粒都比较饱满 ,保持系的网脊细 ,网眼大。实验还表明 ,该玻里马不育系转育容易 ,在大白菜。

水稻光温敏雄性核不育系生态育种的理论与实践(综述)

根据光温敏核不育水稻农垦88S的温光反应特性及其遗传特点，长江流域对实用籼型光温散核不育系的要求，利用我国丰富的光温资源，提出光温敏核不育系的生态育种法，已选育出一批较为实用的光温敏核不育系，并发现光温敏核不育再生复育（MSRF）两用系新类型．

粳稻三系亲本亲子间性状相关性分析

[目的]研究粳稻三系亲本亲子间性状的相关性。[方法]以BT型粳稻不育系、保持系及恢复系各16个为供试材料,配制229个杂交粳稻组合,测定其农艺性状、产量性状和品质性状,并对数据进行相关性分析。[结果]杂种的多数性状由不育系和恢复系共同决定,杂种与中亲值的相关性最好,杂种与高亲值的相关性一般好于与低亲值的相关性。抽穗期、穗总粒数等性状与不育系关系较为密切,株高、穗实粒数、结实率、单株产量、品质性状与恢复系关系较为密切。所有产量性状亲子间的相关系数均小于0.7,说明杂种的产量性状还与双亲的特殊配合力有密切的关系。[结论]该研究为杂交粳稻育种提供配合力好的亲本资源,并为生产应用提供优质高产的杂交粳稻组合。

玉米CMS–C型雄性不育系C543恢复基因的初定位

以玉米恢复系614、B137分别与CMS–C型雄性不育系C543组配的F2代(614群体和B317群体)为试材,进行花粉育性鉴定和遗传分析。花粉育性镜检发现,C543花药内没有花粉,属于无花粉型雄性不育;遗传分析表明,C543的不育性状由1对隐性核基因控制,恢复系614和B137各有1对核恢复基因;SSR标记连锁分析结果将恢复基因定位在玉米8号染色体短臂上,位于标记umc1483附近,两者距离约16.9 c M。

甘蓝型油菜改良型不育系RGCMS-1141A的选育

利用作者提出的“植物细胞核 +细胞质雄性不育”的理论 ,对在生产上大面积推广的甘蓝型油菜波里马细胞质雄性不育优质杂交种“华杂 4号”的亲本不育系 1141A进行遗传改良 ,选育出遗传背景基本保持不变的油菜细胞核 +细胞质雄性不育系RGCMS 1141A及其保持系RGCMS

质核互作型红麻雄性不育系LC0301A的选育

为了提高红麻产量,解决过去通过化学杀雄利用杂种优势的问题,运用发现的雄性不育系材料进行遗传改良,选育出稳定的雄性不育系。以发现的红麻不育材料155为供体,充分利用丰富优良的种质回交,育成了配合力高和育性稳定的不育系红茎晚熟型LC0301A和相应的红茎晚熟型保持系LC0301B。

甘蓝型油菜雄性核不育系快速繁殖及其植株性状的初步研究

利用甘蓝型油菜核不育株苔段，经过分化、增殖、诱导生根等室内培养及田间栽培，可快速得到大量遗传特性不变的再生核不育植株。该不育株系不育株率达１００％，与可育亲本的配合力较强，丰产性较好。利用雌性核不育系快速繁殖法获得的不育系应用于杂交一代种的制作，可增加制种产量，提高制种纯度，省工省时。

自然昆虫传粉转Bt基因棉花核质不育系的主要性状研究

研究了昆虫自然传粉条件下转Bt基因棉、常规棉核质不育系及其相应同核异质保持系的主要经济性状。结果表明 :不育系的单株成铃、衣分、霜前籽棉和皮棉产量极显著低于保持系 ,子指显著高于保持系 ;转Bt基因不育系的单铃重显著低于保持系 ,霜前种子产量差异不明显 ;转Bt基因不育系霜前种子产量极显著高于常规不育系 ;转Bt基因不育系昆虫自然授粉率比常规不育系大幅提高。