水稻雄性不育系的胚囊育性及其对异交结实的影响

以3个光温敏核不育系W7415S、安农S、培矮64S和4个质核互作雄性不育系珍汕97A(夜公胞质)、珍汕97A(野败胞质)、华农A(夜公胞质)和华农A(野败胞质)为材料,通过观察各不育系成熟胚囊结构,并对异交结实率进行调查,以明确水稻雄性不育系异交结实率是否与胚囊育性有关.结果表明:不同水稻雄性不育系的胚囊育性与异交结...     

不同授粉方式的花粉密度分布与结实效应研究

运用空中花粉捕捉法测定了风机、竹竿、绳索等３种不同人工辅助授粉方式的田间花粉密度空间分布状态，并取样调查了其母本异交结实率。结果表明，风机授粉的田间花粉密度在母本穗层的水平分布与垂直分布均比竹竿、绳索授粉的均匀，母本异交结实率比竹竿授粉提高１５．３％。本试验认为，采用风机授粉是今后人工辅助授粉的发展方向，是进一步提高制种产量的有效授粉方式。     

水稻(Oryza sativa L.)温敏核不育系在有利于遗传型鉴别环境下的遗传改良

低不育起点温度(CSP)、高自繁育性和高的异交结实率对于水稻温敏核雄性不育系配制纯合的杂交种子和获得经济的自繁种子有重要意义。本研究分析了不同环境对这些性状选择效率的影响，结果表明，温敏核雄性不育系的雄性不育起点温度、自繁雄性可育性、柱头外露率和穗伸出率、生长势和适应性的选择效应受环境影响。在某种环境下遗传材料的这些性状过高的表达并没有导致高的区分度，因为在这种情况下性状在株间表现较整齐一致，温敏核雄性不育基因(tms)在高温下雄性不育性也表现相似的结果，因此认为有必要在适当有利于区分遗传型的环境下进行选择。在相对较低的温度条件下选择低的CSP和高的自繁雄性可育性有较高的选择效率；在较高的湿度条件下选择柱头外露较有效，而高的温度下选择穗的抽出率效率高．在相对低的土壤肥力环境下改良不育系的生长活力和适应性效率高。     

披碱草属植物的种间杂交和种质创新

披碱草属Elymus植物是小麦Triticum nestizum、大麦Hordeum vulgare的近缘属,同时蕴藏着丰富的优良基因,是改良小麦、大麦和黑麦Sacale cereale品种的优良基因资源。披碱草属植物也是草原和草甸的重要组成成分,具有极高的饲用价值和重要的水土保持功能,但国内在披碱草属植物资源和利用方面的研究与我国具有丰富的资源极不相称。现从国内外对披碱草属植物种间杂交利用方面进行论述,为充分开发利用我国丰富的披碱草属植物资源进行种质创新提供有价值的信息。     

五脉山黧豆开花动态及有性繁育系统的研究

观测了五脉山黧豆的开花动态,并用杂交指数(OCI)、花粉-胚珠比(P/O)方法测定了其有性繁育系统类型。结果表明,五脉山黧豆的花期持续45 d左右,盛花期为6月下旬左右。开花的日动态呈明显的双峰现象,2峰分别在8:00-11:00和14:00-15:00时出现。五脉山黧豆的杂交指数(OCI)=3,繁育系统为自交亲和,有时需要传粉者;花粉-胚珠比(P/O)=2 286.21,为兼性异交。得出其繁育类型为混交繁育系统,即自交和异交并存。五脉山黧豆的传粉系统不完善和虫害是结实率低的主要原因。     

Innate factors causing differences in gene flow frequency from transgenic rice to different weedy rice biotypes

BACKGROUND: The compatibility and outcrossing rates between transgenic rice and weedy rice biotypes have been studied in some previous cases. However, few studies have addressed the reasons for these differences. The present study compared the compatibility and outcrossing rates between transgenic rice and selected weedy rice biotypes using manual and natural crossing experiments to elucidate the key innate factors causing the different outcrossing rates. RESULTS: Hybrid seed sets from manual crossing between transgenic rice and weedy rice varied from 31.8 to 82.7%, which correlated directly with genetic compatibility. Moreover, the significant differences in the quantity of germinated donor pollens and pollen tubes entering the weedy rice ovule directly contributed to the different seed sets. The natural outcrossing rates varied from 0 to 6.66‰. The duration of flowering overlap was the key factor influencing natural outcrossing. Plant and panicle height also affected outcrossing success. CONCLUSION: From this study, it is concluded that the likelihood of gene flow between transgenic rice and weedy rice biotypes is primarily determined by floral synchronisation and secondarily influenced by genetic compatibility and some morphological characteristics. Copyright © 2011 Society of Chemical Industry     

2个三系水稻不育系的生育特性和异交特性研究

对新育成的水稻籼型三系不育系伍谷A和佳谷A的基本生育特性及异交习性进行初步研究,结果表明:伍谷A和佳谷A的株高比对照谷丰A(CK)矮,单穗颖花数均略高于对照,播始历期分别为70~84 d和72~80 d。2个不育系单穗日开花动态和花时分布情况与谷丰A基本相当,表现为开花高峰期明显,花时集中,午前花率都达80%以上;柱头外露率均高于对照,伍谷A和佳谷A的总柱头外露率分别为79.32%和70.80%,但包颈程度和柱头活力持续时间较为不理想。     

Genetic diversity within and between sulfonylurea‐resistant and susceptible populations of Schoenoplectus juncoides in Japan

To reveal the effects of herbicide selection on genetic diversity in the outcrossing weed species Schoenoplectus juncoides, six sulfonylurea‐resistant (SU‐R) and eight sulfonylurea‐susceptible (SU‐S) populations were analysed using 40 polymorphic inter‐simple sequence repeat loci. The plants were collected from three widely separated regions: the Tohoku, Kanto and Kyushu districts of Japan. Genetic diversity values (Nei's gene diversity, h) within each SU‐S population ranged from h = 0.125 to h = 0.235. The average genetic diversity within the SU‐S populations was H_S = 0.161, and the total genetic diversity was H_T = 0.271. Although the H_S of the SU‐R populations (0.051) was lower than that of the SU‐S populations, the H_T of the SU‐R populations (0.202) was comparable with that of the SU‐S populations. Most of the genetic variation was found within the region for both the SU‐S and SU‐R populations (88% of the genetic variation respectively). Two of the SU‐R populations showed relatively high genetic diversity (h = 0.117 and 0.161), which were comparable with those of the SU‐S populations. In contrast, the genetic diversity within four SU‐R populations was much lower (from h = 0 to 0.018) than in the SU‐S populations. The results suggest that selection by sulfonylurea herbicides has decreased genetic diversity within some SU‐R populations of S. juncoides. The different level of genetic diversity in the SU‐R populations is most likely due to different levels of inbreeding in the populations.     

郴州地区1994年杂交水稻制种减产原因分析及对策探讨

论证了全区制种授粉期遇高温干燥火南风，结实率低是减产的主要原因，成熟期遇连阴雨种子穗上发芽加剧种子减收。根据高产基地多年研究成果，探讨选择好基础，安排好授粉期，实施好降温增辅助措施以及科学施用穗粒肥；微肥；调节父线本花时，变换人工辅助授粉方式，推广低容量喷“九二０”，施用抗穗萌剂减少减少穗上发芽等高产、稳产、高效制种对策。     

不育系柱头外露率及其结实率研究

对生产上常用的汕Ａ、优ⅠＡ、枝Ａ、金２３Ａ、Ⅱ－３２Ａ和新不育系新香Ａ的柱头外露及其结实率进行了研究，探索了春、夏、秋三季制种不育系柱头外露率及结实率的变化。有利于充分发挥柱头外露率潜力的是春季制种