两份太空诱变玉米雄性不育突变体的遗传研究

从搭载神舟4号飞船的4份玉米自交系后代中选育出两份雄性不育突变体, 对其进行育性鉴定, 并分析不育性状的稳定性及遗传特点。以不育材料的不育株为母本, 同群体的可育株和其他自交系为父本进行杂交, 结合自交、回交分析其后代的育性表现; 同时, 以具有正常细胞质的自交系为母本, 育性完全恢复的测交F1植株为父本进行反交, 对其反交的F1及F2进行育性观察分析。结果表明：这两份不育材料不育株的花药内无花粉或含少量畸形花粉, 败育彻底, 花粉败育表现为典败型。不育性状在不同年份、不同季节、不同地点下稳定遗传, 属可遗传的单基因控制的隐性核不育类型。     

水稻雄性不育突变体ms102的鉴定和基因定位

水稻(Oryza sativa)隐性核雄性不育突变体是第三代杂交水稻技术的核心。为了挖掘优质雄性不育突变体, 该研究通过筛选优质籼稻黄华占(HHZ)的甲基磺酸乙酯(EMS)诱变突变体库, 获得1个雄性不育突变体ms102 (male sterility mutant 102)。该突变体营养生长正常, 但花药不开裂, 花粉败育。细胞学分析表明, 突变体花药绒毡层不能正常降解, 导致小孢子发育异常; 遗传分析表明, 该突变体的不育表型由1个已报道编码酰基转移酶的DPW2基因突变造成。研究获得了1个隐性核雄性不育突变体, 进一步证实了DPW2基因在水稻花药发育中的功能。     

棉花光敏雄性核不育突变体PSM4创制及其特性研究

为了创造棉花光敏雄性不育系材料,解决杂交制种中人工去雄成本高的问题,自2006年起进行了大规模组织培养,创造棉花突变体,以期筛选出棉花光敏雄性不育材料。2012年在组织培养再生植株后代中发现新型光敏核不育材料PSM4(photoperiod sensitive male sterility mutant of cotton),并于2012~2017年在海南三亚吉阳镇中寥村中棉所南繁基地和安阳中棉所试验田进行材料选育、生长发育调查及光周期实验。结果表明:(1)PSM4在日照时数大于12h时表现为雄性不育;在日照时数为11.5~12h时表现为有少量花粉,处于育性转变期;在日照时数小于11.5h时表现为正常可育。(2)遮光试验显示,PSM4花药败育关键时期为开花前12~15d;石蜡切片显微观察显示,花药败育原因是在长日照条件下花粉壁外层物质缺失引起的。(3)遗传规律研究显示,PSM4育性受单隐性基因控制,不受阴雨气候条件影响。(4)用6个棉花品系与PSM4进行正反交试验发现F1代均可育,F2代分离出光敏核不育单株,分离比符合3∶1的单隐性分离规律。研究认为,新型棉花光敏核不育材料PSM4农艺性状优良,其光敏不育突变为隐性性状,所有的陆地棉品种(系)均为其恢复系,有利于杂交种的培育和棉花混选混交育种群体的建立,具有广阔的应用前景。     

合成甘蓝型油菜中双隐性雄性核不育材料的发现及遗传规律分析

从甘蓝型油菜与白菜型油菜的种间杂交获得的甘蓝型油菜(Brassica napus)中发现了雄性不育单株,兄妹交株系和不育株与甘蓝型油菜常规杂交F1和F2株系的育性分离分析表明,该不育材料属于双隐性雄性核不育类型.利用育性分离株系的可育株自交和可育株与不育株间兄妹交等方法筛选出7个纯合可育株系,等位测验表明这7个纯合可育株系(B1～B7)中存在两种基因型:Ms1Ms1ms2ms2和ms1ms1Ms2MS2.该材料对油菜核不育基因定位和杂种优势利用研究有重要意义.     

首例航天诱变玉米雄性不育突变体的遗传分析

将卫星搭载处理后代所得到的玉米雄性不育材料,在不同地点、不同年份、不同季节进行种植观察;从田间和室内对育性表现的稳定性进行鉴定。通过正交和反交对不育株的所属类型进行分析,结合自交、回交分析其遗传特点。结果表明,该不育材料的雄穗无任何花药外露,花药内无花粉粒,败育彻底,育性表现稳定,是一个由隐性单基因控制的可遗传的“无花粉型”核不育。     

枸杞胼胝质酶基因克隆及在雄性不育材料中的表达分析

以雄性不育枸杞‘宁杞5号’和正常可育枸杞‘宁杞1号’为材料,提取不同发育时期枸杞花蕾RNA,反转录合成cDNA,利用胼胝质酶的β-1,3-葡聚糖酶属性进行同源克隆和半定量RT-PCR分析.结果表明:(1)所克隆的胼胝质酶基因(LG1)属于植物糖基水解酶第17家族基因,编码344个氨基酸,有5个氨基酸保守区在4种植物的花药β-1,3-葡聚糖酶基因中都存在.(2)LG1在正常可育枸杞花药中高量表达,在雄性不育枸杞花药中表达沉默,但基因序列并没有发生突变.(3)经苯胺蓝染色观察,雄性不育枸杞花药四分体分解受阻与LG1基因表达沉默同步.研究结果提示,LG1基因是受不育基因调控的下游基因,参与了枸杞花粉的败育过程,LG1基因沉默是雄性不育枸杞花粉败育的一个重要原因.     

水稻雄性不育与可育花药的mRNA差别显示和cDNA差别片段的分析

用mRNA差别显示 ,对水稻细胞质雄性不育系、保持系和F1杂种的花药mRNA和叶片mRNA进行了比较和分析 ,以研究雄性不育花药在花粉败育时期的基因表达方式 .花药在不育与可育间显示的cDNA差别带数多于叶片 ,表明在花药中育性基因的表达比叶片中活跃和充分 .不同类型花药的基因转录方式既与花药育性程度有关也与花药败育早晚有关 ,不育、部分不育和早期败育的花药所显示的cDNA差别带数多于可育和晚期败育的花药 .在回收的 1 2个cDNA差别片段中 ,有2个可能与雄性不育相关 ,AB₄A₅ 片段只在不育花药中专一表达 ,另一片段AB₃ B₂ 含有与线粒体基因coxⅡ同源的序列 ,在不育花药中的表达受到部分抑制     

拟南芥雄性不育相关基因LDAD1&2的遗传定位(英文)

利用EMS诱变筛选手段分离到一株拟南芥类似花药不开裂雄性不育突变体(like-defective in anther de-hiscence,ldad),其果荚干瘪,花药不能开裂且花粉败育。遗传分析表明,突变体的表型受2个隐性基因控制;细胞学观察发现,在花药发育过程中伴随着小孢子的降解;通过图位克隆初步对ldad的2个突变位点分别定位,一个定位在1号染色体上SSLP标记F22L4与端粒之间171 kb的区间,另一个定位在5号染色体上SSLP标记T10O8与端粒间150 kb的区间内;生物信息学分析显示此区间内未见育性相关的已知基因。该研究的结果对进一步克隆LDAD1&2基因及探讨其在花药发育中的功能具有重要意义。     

长春蒲公英雄性不育株形态学观察与败育细胞学研究

在长春蒲公英(Taraxacum junpeianum Kitam.)株群中发现雄性不育现象,为研究其败育机理及特点,探寻其不育基因,采用形态观察法、石蜡切片技术和染色体压片法,对长春蒲公英野生型及其雄性不育株的花药发育过程和花粉母细胞减数分裂过程进行了观察。结果表明:(1)长春蒲公英雄性不育株花药中部发红、干瘪、无花粉散出。与野生型比较,雄性不育株雄蕊更短,子房更窄,种子形态更加狭长;(2)长春蒲公英雄性不育株败育时期为四分体到单核小孢子前期,败育方式为小孢子自身异常发育,绒毡层异常分解,互相粘连败育;(3)长春蒲公英雄性不育株花粉母细胞减数分裂二分体时期出现落后微核,随后产生极少四分体,并且四分体产生大量染色体桥,小孢子营养物质流失,彻底败育。因此,长春蒲公英雄性不育株败育彻底、稳定,并且有种的特点。小孢子自身异常发育和绒毡层异常分解是导致败育的主要原因。     

水稻野败型雄性不育系花粉败育的解剖学和细胞学观察

关于植物雄性不育的小孢子发生的组织学和细胞学研究,过去曾有过不少报道。Laser和Lersten曾对自1925年起至1972年4月1日止的文献作了综合性的评论。在该文的表1中列举了曾研究过的植物种类,均未提及水稻。近年来,国内外也有人对水稻雄性不育的小孢子发生过程进行了细胞学的观察。我室自1975年起,除观察水稻雄性不育的小孢子发生过程外,主要对花药的毡绒层及花丝组织进行了解剖观察,以探索其花粉败育的原因。据我们的观察结果,不同类型的水稻雄性不育系,其花粉的败育过程也不完全相同。因此,需要对不同类型的水稻雄性不育系的花粉败育过程分别加以研究。本文主要报道对野生稻花粉败育型雄性不育系进行观察的结果。     

（普通小麦／长穗偃麦草）F1小孢子发生和雄配子体发育的细胞学特点

试验用压片法对（普通小麦／长穗偃麦草）Ｆ１小孢子发生和雄配子体发育进行了细胞学观察．观察表明：１．（普通小麦／长穗偃麦草）Ｆ１花粉母细胞减数分裂过程中出现许多异常现象;在ＰＭＣ Ｍ１出现较高频率的单价体和多价体;但是减数分裂过程能够完成,并且四分孢子的败育率较低。２．在雄配子体发育过程中可观察到具有多微核、体积不等的小孢子,并发现经过对称孢子有丝分裂产生的二胞花粉;在花粉发育的不同时期均可观察到花     

Nuclear-cytoplasmic interactions reduce male fertility in hybrids of Arabidopsis lyrata subspecies

We examined the level of postzygotic reproductive isolation in F(1) and F(2) hybrids of reciprocal crosses between the Arabidopsis lyrata subspecies lyrata (North American) and petraea (European). Our main results are: first, the percentage of fertile pollen was significantly reduced in the F(1) and F(2) compared to the parental populations. Second, mean pollen fertility differed markedly between reciprocal crosses: 84% in the F(2) with ssp. lyrata cytoplasm and 61% in the F(2) with ssp. petraea cytoplasm. Third, 17% of the F(2) with ssp. petraea cytoplasm showed male sterility (produced less than 30 pollen grains in our subsample). The hybrids were female fertile. We used QTL mapping to find the genomic regions that determine pollen fertility and that restore cytoplasmic male sterility (CMS). In the F(2) with ssp. lyrata cytoplasm, an epistatic pair of QTLs was detected. In the reciprocal F(2) progeny, four QTLs demonstrated within-population polymorphism for hybrid male sterility. In addition, in the F(2) with ssp. petraea cytoplasm, there was a strong male fertility restorer locus on chromosome 2 where a cluster of CMS restorer gene-related PPR genes have been found in A. lyrata. Our results underline the importance of cytonuclear interactions in understanding genetics of the early stages of speciation.     

Variation in sporophytic and gametophytic vigor in wild and cultivated varieties of Cucurbita pepo and their F1 and F2 generations

 This study examines sporophytic and gametophytic vigor in wild and cultivated varieties of Cucurbita pepo L. and their hybrids in order to determine whether hybrid vigor extends to the microgametophyte generation. It also examines the variation in sporophytic and gametophytic vigor to discern the non-genetic influences of pollen provisioning by the sporophyte on pollen performance from the genetic influences of the microgametophyte’s own genotype on pollen performance. A cultivated and a wild C. pepo and their F1 and the F2 generations were grown under field conditions and flower and fruit production were monitored over one summer. We found that the four types of plants differed significantly in the number of male and female flowers and the number of fruits they produced. The F1 plants produced significantly more male flowers and marginally more female flowers and fruits than the parental lines. To estimate gametophytic vigor pollen was germinated in vitro and pollen tube length measured after 30 min. We found that pollen tubes from the F1 plants had significantly greater growth than tubes from the parental lines or the F2 generation, indicating that hybrid vigor extends to the microgametophytic generation. By partitioning the variance of pollen tube growth into ’within’ and ’among’ plant components of variation, we were able to show that the genotype of the microgametophyte influences pollen performance in vitro, but that expression of hybrid vigor in the microgametophyte is likely to be due to an environmental effect related to provisioning of the pollen grains during development. Received: 16 April 1998 / Revision accepted: 18 August 1998     

Evaluation of diets for the development and reproduction of Franklinothrips orizabensis (Thysanoptera: Aeolothripidae)

The suitability of ten diets for the development and reproduction of Franklinothrips orizabensis Johansen, the key natural enemy of Scirtothrips perseae Nakahara, a pest of California grown avocados, was determined in the laboratory. The experimental diets evaluated were: (i) irradiated Ephestia kuehniella Zeller eggs; (ii) irradiated E. kuehniella eggs and avocado pollen; (iii) Tetranychus pacificus McGregor eggs; (iv) T. pacificus eggs and avocado pollen; (v) irradiated E. kuehniella eggs and T. pacificus eggs; (vi) irradiated E. kuehniella eggs, T. pacificus eggs and avocado pollen; (vii) Scirtothrips perseae; (viii) Heliothrips haemorrhoidalis (Bouchè); (ix) avocado pollen; and (x) a young avocado leaf. Franklinothrips orizabensis larvae were unable to develop to adulthood on diets 9 and 10. The remaining eight diets supported complete development of F. orizabensis, but only diets 1, 2, 5, 6, 7 and 8 produced fecund females. On diet 5, F. orizabensis exhibited high larval to adult survivorship (90%), mated females exhibited highest daily and lifetime fecundity, and the progeny of mated females were female biased (53%). Analysis of jackknife estimates of net reproduction (Ro), intrinsic rate of increase (rm), and finite rate of increase (lambda) were all significantly greater for F. orizabensis reared on irradiated E. kuehniella eggs and T. pacificus eggs (i.e. diet 5) than corresponding values for other diets on which female F. orizabensis were able to complete development and reproduce. Incorporation of avocado pollen into diets had an adverse effect on demographic statistics for F. orizabensis, and low quality diets resulted in male biased sex ratios for this predator.     

融安金柑雌雄配子发育相关性及2n配子诱导研究

以融安金柑为试验材料,观察了2n花粉自然发生率、雌雄配子发育过程及减数分裂行为,以不同秋水仙素浓度及处理时间对花蕾进行2n配子诱变.结果显示:(1)融安金柑2n花粉自然发生率为0.31％;(2)花蕾纵径为0.228～0.270cm时,为花粉母细胞减数分裂Ⅰ前期;花蕾纵径为0.274～0.318 cm时,大孢子处于减数分...     

Gametophytic expression of genes controlling endosperm development in maize

Summary An indirect approach was adopted to select viable mutants affecting the male gametophytic generation in maize. This approach consists of a selection of endosperm defective mutants followed by a test for gametophytic gene expression, based on the distortion from mendelian segregation and on the measurement of pollen size and pollen sterility. The material used consisted of 34 endosperm defective viable mutants introgressed in B37 genetic background. Complementation tests indicated that the mutation in the collection of mutants affected different genes controlling endosperm development. The study of the segregation in F2 revealed four classes of de (defective endosperm) mutants: (1) mutants in which the mutation does not affect either gametophytic development or function; (2) mutants in which the effect on the gametophyte affects pollen development processes; (3) mutants showing effects on both pollen development and function, and (4) mutants where only pollen tube growth rate is affected. Positive and negative interactions between pollen and style were detected by means of mixed pollination (pollen produced by de/de plants and pollen from an inbred line used as a standard and carrying genes for colored aleurone), on de/de and de/ + plants. Positive interactions were interpreted as methabolic complementation between defective pollen and normal styles.     

新型甘蓝型油菜温敏核不育系SP2S的花药发育解剖学观察

SP2S是西北农林科技大学选育的甘蓝型油菜温敏核不育系,本文采用半薄树脂切片、扫描电镜对SP2S及其可育近等基因系SP2F的花药发育及花粉形态进行观察比较,发现SP2S花药发育在减数分裂时期出现异常,单核花粉时期彻底败育。其主要特征是：减数分裂时期绒毡层已经径向肥大且出现大液泡,胼胝质不能及时降解,使得单核小孢子相互粘连在一起,小孢子无花粉壁的形成且细胞质物质逐渐降解,最后小孢子仅剩下空壳残留物,聚集在一起。SP2S败育特征与现有的核不育材料不同,表明其有可能是一种新型温敏核不育材料。     

Abnormality in Male Organ Development and Fertility of Photoperiod sensitive Genic Male Sterile Rice Plants Under Short Day Condition

Ten photoperiod-sensitive genic male sterile rice (PGMSR) lines were studied to observe the development of male organs of their short day (SD) plants. The results were shown as follows: 1 ) The self seed-setting rate and the percentage of fertile pollen of these PGMSR lines were much lower than those of the controls. 2) All the male sterile line plants had variant barriers in anther dehiscing and pollen scattering. In addition, some of their stigmas were devoid of pollen, and some self pollen grains on their stignas germinated weakly. 3) Female fertility of those plants was believed to be normal through observation in their embryo sac development and cross seed-setting rate. The authors deduced that the male sterile gene expression becomes the major factor for low rate of self seed-setting of PGMSR plants under SD condition.