Development of Japonica Male Sterile Lines Integrating Cytoplasmic Male Sterility and Photosensitive Genic Male Sterility

Acknowledgement It has been previously established that the BT type of cytoplasmic male sterility （CMS） is induced by high temperatures, while photosensitive genic male sterility （PGMS） seed sets by low temperatures induce. In the current study, we have bred photosensitive cytoplasmic male sterility （PCMS） lines （2308SA and 2310SA） by crossing the CMS line with the PGMS japonica line with maintainer genes. The sterility of PCMS japonica was consequently controlled by two groups of male sterile genes resulting from the integration of PGMS and CMS genes. The results on plant fertility, at different sowing times, were as follows： （a） Under conditions of natural long-day photoperiod and at temperatures above 35~C, the PGMS gene regulated PCMS japonica sterility - the higher the temperature, the lower the pollen fertility. However, bagged seed sets of PCMS japonica, not exposed to high temperatures, induced the CMS seed set. （b） Exposure to long-day photoperiod and temperature conditions between 35℃ and the critical sterility inducing temperature of PGMS resulted in both PGMS and CMS gene controlled sterility of PCMS japonica, which exhibited stable characteristics. （c） When exposed to critical sterility inducing temperatures or short-day photoperiod and daily high temperatures below 32℃, the BT type of the CMS gene regulated PCMS sterility. Under these conditions, the PGMS gene rendered male sterility insusceptible to occasional cool summer days when this PCMS line, adopted for hybrid seed production, develops into panicle differentiation stage. The present study also investigated the fertility restoration, seed production and combining ability of PCMS japonica so as to optimize its use.     

Genetics of Fertility Restoration in Cytoplasmic Male Sterile Pepper

Pepper hybrid seeds production using male sterility could lower cost by reducing time and labour, and increase the genetic purity of the F1 seeds. To investigate the genetics of fertility restoration of the Peterson cytoplasmic sterility in pepper, a doubled haploid population of 115 pepper lines obtained from anther culture of the F1 hybrid between Yolo Wonder （sterility maintainer line） and Perennial （fertility restorer line） and the parental lines were test-crossed by 77013A （a strict cytoplasmic-genic male sterile line）. The fertility of the test-crossed lines was assessed in greenhouse and open field with the following three criteria： pollen index （PI, visual estimation of pollen amount per flower）, pollen number （PN, pollen counting under microscope）, and seed number （SN, the number of seeds per fruit in open pollination）. Correlations between the each couple of criteria within, as well as between the cultivation methods ranged from 0.55 to 0.84. Analysis of variance showed that the genotype （DH line） and environment were the significant sources of variation of the fertility. Narrow sense of heritance of fertility restoration ranged from 0.38 to 0.92, depending on the criteria and environment. The distribution of the progeny was continuous between the parental genotypes indicating the quantitative inheritance of fertility restoration. Inferred from segregation according to Snape et al.（1984）, the number of segregating genes was estimated to be that three to four genetic factors were involved in pollen traits （PI and PN） and five to eight genetic factors in seed production （SN）. The heredity analysis of the CMS will be helpful for understanding of the genetic mechanism of the fertility restoration and the exploitation of the CMS in hybrid seed production.     

Approaches for Preventing the Male Sterility Fluctuation of Photo- thermo- sensitive Genic Male Sterile Lines in Rice

The male sterility fluctuation of photo-thermo-sensitive genic male sterile[P(T) GMS] lines induced by low air temperature is a key problem troubling the application of two-line system hybrid rice. The paper suggests to solve this problem by the breeding approaches, i. e, de-veloping low sterile critical temperauare P(T)GMS lines, herbicide resistant restorer lines, herbi-cide sensitive P(T)GMS lines and tetracycline- conditioned P(T)GMS lines to ensure the hybrid purity; and by the hybrid seed production techniques, i. e, taking the correct procedure of foun-dation seed production, the suitable district and season for hybrid seed production and the deep ir-rigation method against cold weather in high summer.     

Directional Breeding of An Oval-ecotype Male Sterile Line of Chinese Cabbage(Brassica campestris L. ssp. pekinensis)

[目的]探究大白菜定向转育卵圆生态型雄性不育系的方法。[方法]以大白菜核不育＂复等位基因遗传假说＂为理论依据,以甲型两用系‘AB12’为不育供体品系,以卵圆生态型可育品系‘06048’为待转育品系,采用杂交、回交、兄妹交和测交的方法,按照定向转育方案将核不育基因定向转育。[结果]各世代育性分离比率与理论相一致,成功育成了一种不育株率100%的具有‘06048’园艺性状的新核不育系,实现了核不育基因和园艺特性的同时转育。[结论]该研究成果验证此定向转育方案是可行的,进一步为基因型为 msms的其他园艺性状的大白菜定向转育提供理论基础,也可以推广应用到整个芸薹属其它经济作物中,极大的拓宽了优良核不育基因的实际应用范围。     

Plant Temperature for Sterile Alteration of a Temperature-Sensitive Genic Male Sterile Rice, Peiai64S

The forecast of sterile alteration for the temperature-sensitive genic male sterile （TGMS） line in two-line hybrid rice seed production was traditionally based on screen temperature determined by weather station. The article put forward a new approach based on plant temperature, which was more exact and direct than the traditional method. The result of the simulation of the self-seeded setting rate of a widely used TGMS line, Peiai64S, by several temperature parameters and durations, showed that the fertility was directly affected by the plant temperature at a height of 20 cm or the air temperature around it in three days duration. Using the stem temperature of three days at a height of 20 cm as the simulation parameter, the fertility of Peiai64S had the maximum, minimum and optimum temperatures as 22.8, 21.7 and 22.5℃, respectively, whereas 23.2, 21.5 and 21.8℃ when using the air temperature of three days around the height of 20 cm as the parameter. Such temperature indices can be used to conclude the sterile alteration of TGMS for safeguarding seed production of twoline hybrid rice. The article also established a statistic model to conclude plant temperature by water temperatures at inflow and outflow, and air temperature and cloudage from weather station.     

RNA Interference-Mediated Downregulation of sAC Gene Inhibits Sperm Hyperactivation in Male Rats （Rattus norvegicus）

Hyperactivation is one of the most critical parts for fertilization, cAMP generated by soluble adenylyl cyclase （sAC） is necessary to activate sperm and is a prerequisite for sperm hyperactivation. The aim of this study is to investigate the function of sAC in hyperactivation in male rats. Four siRNAs of sAC gene were designed and separately transformed into rat sperm using electrotransformation method. Cultured for 12 and 24 h, physiological and biochemical indexes of these sperm were analyzed, and the expressions of some hyperactivation-related genes were detected using real-time PCR. We demonstrated 26.3-30.8% and 49.1-50.5% reduction in sAC at the protein by Western blot and mRNA levels by real-time PCR, respectively. The results showed that two siRNAs, Actb-717 and Actb-4205, were the best RNAi sites for silencing sAC. The VCL （curvilinear velocity） and ALH （amplitude of lateral head displacement） of RNA interference （RNAi）-transfected sperm were reduced, cAMP and protein phosphorylation in RNAi transfected sperm were also decreased. The hyperactivation-related genes, such as CatSper2, LDHC and PKA, were downregulated in the sperm, which sAC was knockdown. These findings demonstrated that sAC might play a critical role in cAMP signaling in the rat sperm hyperactivation, and downregulated sAC gene might prevent the expression of these hyperactivation-ralated genes resulting in sperm dysfunction. These findings suggest that these hyperactivation-ralated genes and sAC are functionally related in sperm hyperactivation and sAC falls into an expanding group of sperm proteins that appear to be promising targets for the development of male contraceptives.     

Analysis on Combining Ability for Characters of Male Sterile Lines in Rapeseed （ Brassica napus L.）

The male sterile line is very important in the hybrid breeding program of rapeseed. This study was conducted to evaluate the combining ability of many characters of male sterile lines in Brassica napus...     

Study on Quality Improvement Effect and Separate Character of Soybean Male Sterile （MS1） Recurrent Selection Population

To solve the problem that soybean has narrow genetic base, we constructed a series of male sterile recurrent selection populations, and studied the effects of quality improvement and practical value. An LD-base population, which fits to our ecology type was constructed by 6 years＇ gene enrichment through the introduction of new genes from 23 local varieties and recurrent selection. The LD-base populations were then improved by making crosses with high protein and high oil genotypes. As a result we obtained a high protein sub-population （db） and a high oil sub-population （gy）, For the db sub-population, the protein content is 1.18% higher than the base population, 22.38% of the individuals contain 45% or more of protein, which is 10.99% higher than the base population. For the gy sub-population, oil content is 0.24% higher than the base population. Individuals with oil content of 20% or more are 11.05% higher than the base population. The quantitative characters such as flowering date, mature date, pod habit, and hilum color, etc., all showed wide range of separation, and the segregation ratio approached balance. The c.v. of branch number of ms1 recurrent population （72.8%） is higher than general cross-population （57.3%）, and the c.v. of 100 seed weight of ms1 （18.1%） is higher than general cross population （16.5%）, the coefficient of variation of plant height, pods per plant, and seeds per pod were not significantly different. It was demonstrated in this paper that the quality character of ms 1 male sterile recurrent selection population was improved by adding new genes. And the segregation of other characters widened, making the populations suitable for the objective of soybean breeding. In this paper, we also discussed the breeding method, key technology, and selection effect of soybean ms 1 population.     

光温敏核不育基因的等位性研究

选用培矮６４Ｓ（代表农垦５８Ｓ）、安农Ｓ－１、衡农Ｓ－１、５４６０Ｓ、新光Ｓ等５种光温敏核不育系，于１９９５年在海南春季可育期内互交，夏季在合肥种植，以花粉败育率、套袋结实率、自然结实率为育性指标，进行核不育基因等位性研究，结果表明：培矮６４Ｓ、安农Ｓ－１、衡农Ｓ－１、５４６０Ｓ的核不育基因位点互不等位，新光Ｓ与培矮６４Ｓ基因位点相同。另选用农垦５８Ｓ转育成的一批籼粳不育系，以培矮６４Ｓ为桥梁亲本，粳型不育系直接与农垦５８Ｓ配组，籼型不育系与培矮６４Ｓ配组，研究方法同上，结果表明参试的不育系均与农垦５８Ｓ等位     

水稻籼型光敏核不育系湖农5S的选育与研究

通过农垦５８Ｓ／激光４号／／献党转育成的湖农５Ｓ，经研究属于籼型光敏核不育系。该不育系的主要特点是：不育起点温度低，达到了粳型光敏核不育系Ｎ５０８８Ｓ的水平，制种安全可靠；转为可育的临界光长要求比Ｎ５０８８Ｓ更短，在湖北不能繁殖，需在低纬度地区冬季繁殖；它柱头外露率高，开花习性较好，有利制种；配合力强，其杂种米质好，抗性较强，可以这配出强优势组合。     

农垦58S转育的四个籼型光温敏核不育系的不育性遗传研究

２５５８Ｓ、２８７７Ｓ、８９０２Ｓ和Ｗ６１５４Ｓ都是粳型光敏核不育系农垦５８Ｓ转育而来的籼型不育系，试验得出２５５８Ｓ是可育临界温度低的温敏系，２８７７Ｓ和对照农垦５８Ｓ是临界温度较低的光敏系，８９０２Ｓ是临界温度较高的光敏系，Ｗ６１５４５是临界温度高的温敏系。这四个籼型不育系与四个常规品种杂交Ｆ＿１育性都正常，同一组合正反交Ｆ１育性没有显著差异。在四川雅安夏季长光照但气温偏低的生态条件下，２５５８Ｓ和２８７７Ｓ与四个常规品种杂交Ｆ２和ＢＦ１育性基本上表现二对基因的遗传分离，而８９０２Ｓ和Ｗ６１５４Ｓ与四常规品种杂交Ｆ２和ＢＦ１育性分离表现不一致，有的组合表现二对基因的遗传分离有的组合则表现不育株显著偏少。由此认为这四个不育系的不育性由细胞核内二对独立遗传的隐性主基因控制，但遗传背景和环境光、温条件对育性分离表现有很大影响。     

4种光温敏核不育水稻在南昌的育性表现

[目的]考查自然条件下4种不育系水稻在南昌的育性情况。[方法]2010年通过分期播种的方法分别对4个不同类型的实用光温敏核不育系准S、Y58S、P88S和培矮64S的育性转换特性进行系统研究。[结果]准S的敏感期为开花前9～10 d,58S的敏感期为开花前11～13 d,培矮64S的敏感期为开花前16～19 d,P88S没有明显的敏感期。从育性转换临界温度来看,准S最低,为27.2℃;培矮64S次之,为27.5℃;58S转换温度最高,为29.3℃。[结论]在南昌地区,培矮64S的育性波动较小,稳定期较长,较其他几个不育系好。     

水稻不育系的广亲和基因检测及籼粳型分析

为鉴定部分水稻不育系的广亲和性和籼粳型,根据籼粳亚种间广亲和基因S5-n在第6染色体存在136 bp片段缺失的特征,设计InDel标记S5136,对培矮64S、广占63S等不育系进行广亲和基因鉴定。利用与栽培稻籼、粳遗传分化密切相关的34个InDel标记,对这些不育系PCR产物的电泳结果进行判读和分析,计算其籼型或粳型基因频率(InDel分子指数法)。结果表明:①三系不育系粤泰A具有广亲和基因S5-n。②两系不育系培矮64S、N111S、C815S等11个不育系具有广亲和基因S5-n。③目前广泛应用于生产的不育系培矮64S、广占63S、Y58S等的籼型基因频率均为0.76～0.91,据此认为具有10%～25%左右粳稻血缘的籼型不育系可能更有利于亚种间杂种优势利用。     

三个籼型光温敏核不育系杂交F_1和F_2代的不育性研究

8902S是光敏性强、可育临界温度较高的光敏不育系，2877S是光敏性强、可育临界温度较低的光敏不育系，而2558S是光敏性弱、可育临界温度低的温敏不育系，它们都是由农垦58S衍生而来的籼型核不育系。这三个不育系杂交，F_1在长光照、偏低气温下均表现稳定的不育性，表明三个亲本的不育主基因是等位的，F_1可育临界温度与低的亲本相近或更低．光敏不育系89025与2877S杂交，F_1与亲本一样，光敏性强；8902S和2877S与温敏不育系25585杂交，F_1表现双亲的中间型，光敏性中等．2877S与25585杂交F_2代不育株，在长光照、偏低气温下表现败育程度高，在短光照下绝大多数表现可育，且其中很多结实率病，光敏性强．还讨论了农垦58S衍生不育系不育主基因的等位性和实用型光敏核不育系的选育方法．     

水稻光温敏核不育系的单株育性观察

以农垦５８Ｓ，７００１Ｓ，５０４７Ｓ，Ｗ６１５４Ｓ，ＫＳ－９，培矮６４Ｓ，安农Ｓ－１和５４６０Ｓ等不同类型的水稻光温敏核不育系为材料，对单株育性的表现进行了观察，结果表明：除安农Ｓ－１外，其它７个不育系株内颖花间育性均存在显著差异，连续套袋自交对降低颖花间的育性差异效果不大；不育期间有少量自交结实，结实粒在穗上的分布是随机的，它们具有与相应不育系一致的光温敏核不育特性。     

水稻两用不育系的籼粳类型、发育感光性和光敏核不育性的相互关系

两系稻育种实践显示 ,以农垦 58s为光敏核不育基因源转育成的籼稻两用不育系大多是温敏型的 ,而光敏型籼稻两用不育系又大多表现为发育的感光性 ,在籼粳类型、发育感光性与育性转换的光敏特性三者之间似乎存在一定联系 .为探索这一问题 ,以杂种 F1花药培养获得的 2个光温敏不育系群体 [一个为随机选育的不育系群体 ,记为 DHS;另一个为育种获得的 (偏 )籼型不育系群体 ,记为 Hs]为材料 ,对上述 3种特性及其相互关系进行了初步研究 .结果表明 ,所有 Hs株系皆为 (偏 )籼型 ,而 DHS株系籼型和粳型皆有 ,但以中间型居多 .DHS和 Hs中约有一半株系表现出一定程度的发育感光性 ,且绝大多数株系的育性转换特性为光温互作型 .在总共 39个株系中 ,仅发现 3个为光敏型 .其中 Hs- 9和 DHS- 2 4的育性光敏效应极显著 ,其温敏和光温互作效应几乎不存在 ,表现为单纯的光敏型 ;DHS- 38的光敏和温敏效应显著 ,但互作效应不显著 ,表明其育性转换可能同时受到光长和温度的独立控制 .未发现单纯的温敏不育型以及发育感温的光敏不育型 .在DHS和 Hs群体中 ,3种特性间相互独立 ,但发育感光性和育性转换的光敏性之间存在一定程度的正相关 .以上研究结合育种实践表明 ,将光敏核不育基因重组到籼稻背景中是可行的 ,而培育早籼光敏不     

核质互作不育和光敏核不育聚合的粳稻不育系选育

 针对粳型核质互作不育系高温自交结实和粳型光敏核不育系低温自交结实的现状,选择BT型核质互作不育系与含有BT型保持基因的粳型光敏核不育系,通过杂交和回交,使雄性核不育基因与核质互作不育基因聚合,育成了粳型光敏核质互作不育系2308SA和2310SA。该不育系的不育性是由两套相互独立的基因系统控制的,分期播种育性观察结果表明,在长日高温下,雄性光敏核不育隐性纯合基因控制水稻不育性,避免了BT型不育基因因穗期受高温影响而导致不育系自交结实;在长日适温下,水稻不育性由核不育基因和核质互作不育基因共同控制而表现稳定;在低温（低于光敏不育系不育临界温度）或短日适温（日最高气温<32℃）下,BT型核质互作不育基因控制水稻不育性,消除了育性敏感期低温导致核不育系"打摆子"造成杂交种子不纯的风险。还对粳型光敏感核质互作不育系的可恢性、可繁性和配合力进行了研究。     

水稻两用核不育系育性转换与温度的相关分析

在贵阳对8个籼型水稻两用核不育系进行了间期为10－15d的分期播种，以套袋自交结实性作为育性考查指标，结果所有核不育系都有稳定不育期和可育或部分可育期表现，且育性转换明显。稳定不育期的长短因不育系不同而有差异，范围在5－33d。自交结实率与日平均气温之间的相关性表明，所有不育系都在幼穗发育的一定阶段内对温度表现敏感，大多数不育系的温度敏感时期在抽前7－24d，培矮64S在抽穗前17－30d。不同不育基因供体来源的不育系对温度敏感时期和持续时间长短存在着差异，同一不育基因供体来源的不同不育系之间，其育性对温度敏感时期和持续时间长短也不相同。