同核异质两系杂交水稻主要农艺性状的细胞质效应研究

以来源于不同地域的8个不同类型水稻品种为细胞质供体,以温敏核不育系株1S、准S作为细胞核供体,通过杂交和连续回交,得到8种细胞质2套核背景的同核异质温敏核不育系,将株1S、准S(为对照)及其同核异质温敏核不育系分别与4个恢复系杂交,得到72个同核异质两系杂交组合,比较分析了新质源杂交组合与对照杂交组合的主要农艺性状。结果表明,细胞质对同核异质两系杂交组合的8个农艺性状均表现出极显著的遗传效应,新质源整体上在大多数农艺性状上都表现出负效应;质核互作对8个农艺性状也均表现出显著的遗传效应。Lemont细胞质对两系杂交组合的全生育期、株高、单株生物产量、单株有效穗、每穗总粒数有显著的负效应,但对结实率有显著的正效应;V20A细胞质对两系杂交组合的全生育期有显著的正效应,对其余性状均表现出显著的负效应,不适合作两系杂交水稻的细胞质源;日本晴细胞质对两系杂交组合的单株生物产量有显著的正效应,而对全生育期与株高有一定的负效应,可在两系杂交水稻育种中加以利用。     

水稻同核异质不育系及其保持系核基因组的SSR分析

以4套共15份同核异质水稻雄性不育系和保持系为试验材料,应用随机分布于水稻12条染色体上的42对SSR引物,分析其核基因组的遗传多样性和亲缘关系。 在15份材料间共检测到63个等位基因,多态性位点百分率为4048%,平均每个位点的等位基因数为1.5个,平均基因多样性为0.18。4套同核异质不育系的平均相同位点为54.5个,占总等位基因数的86.51%,差异位点为8.5个,占13.49%。同核异质的不育系与保持系间具有平均77.78%的相同位点和22.22%的差异位点。同质异核不育系中则具有平均53.97%的相同位点和46.03%的差异位点。同时,获得了一些不育系和保持系的指纹图谱。根据不育系和保持系聚类分析图,在遗传距离为 0.22处划分为3群,第1群包括华农A和华育A不育系及其保持系共8份材料,第2群包括N9A、N10A和N11A等3份科珍2A材料,第3群包括N12A、N13A、N14A和N12 16B等4份珍汕97A同核异质系。同一套同核异质系基本上都优先聚类在一起,与其选育系谱一致。     

同核异质温敏核不育水稻光合特性的细胞质效应

以来源于不同地域的8个水稻品种为细胞质供体,以温敏核不育系株1S、准S作为细胞核供体,分别连续回交12次,得到株1S和准S 2套核背景的同核异质温敏核不育系,比较了新质源不育系与其对照不育系的光合特性。结果表明,在株1S同核异质不育系中,以日本晴为细胞质源的不育系株1-5S的Pn、Fv'/Fm'、Phi PS2和q P均显著大于对照株1S,而以V20A为细胞质源的不育系株1-3S则显著小于对照株1S;在准S同核异质不育系中,以茶陵野生稻为细胞质源的不育系准-8S的Pn、Fv'/Fm'、Phi PS2和q P均显著大于对照准S,而以Lemont为细胞质源的不育系准-7S的Pn、Fv'/Fm'、Phi PS2和q P及以V20A为细胞质源的不育系准-3S的Pn则显著小于对照准S。V20A细胞质对不育系的光合效率有负效应,茶陵野生稻细胞质和日本晴细胞质在特定的质核互作中有明显的正效应。     

同核异质粳稻不育系特性比较

 对由粳稻品种苏秋、六千辛转育成的2套同核异质不育系的不育性、可恢复性、开花习性及异交特性进行了鉴定，结果表明：1）BT型、HL型不育系花粉以染败为主，WA型不育系花粉以典败为主；BT型苏秋A和BT型六千辛A分别有0.06%和3.72%的自交结实率，不育性最不稳定。2）不育系的花粉败育程度影响穗颈伸出剑叶叶鞘的长度，败育越彻底，穗伸出度越短。3）BT型不育系的花时、花期与保持系最为接近；HL型不育系花时稍有滞后，花期相仿；WA型不育系花时明显滞后，花期明显拉长，开花不集中。4）BT型、HL型不育系的异交结实率无显著差异,但明显高于WA型不育系。5）BT型不育系的可恢复性最好，HL型不育系次之，WA型不育系最难恢复。提出了用HL型不育系部分替代BT型不育系的设想，以解决目前生产上杂交粳稻BT型不育系不育性不够稳定及细胞质单一的问题。     

玉米同核异质不育系小孢子发育的mRNA多态性分析

应用cDNA-RAPD技术分析了玉米同核异质不育材料在小孢子发育过程中花粉发育相关基因表达的差异。结果表明,在小孢子发育的相同时期,引物S330在48-2背景下的不同胞质之间存在差异,不同时期差异表现不一;引物S330在黄早四背景下的不同胞质之间未检测到差异,并且小孢子发育的3个时期表现一致。对同核异质不育系和同质异核不育系的比较发现,核背景对mRNA转录的影响大于细胞质,不育胞质T、C、S在48-2背景和黄早四背景下的差异表现不一。根据S330在48-2背景下的扩增结果,发现基于mRNA多态性的相似性比较结果与不育细胞质的败育特点及败育时期具有较好的一致性,即配子体不育类型与保持系的相似性高于孢子体不育类型,孢子体不育类型之间的相似性高于孢子体不育与配子体不育的相似性。     

水稻同核异质不育系材料对白背飞虱抗性的研究初报

采用蜜露量测定法,初步研究了具有不同胞质的水稻同核异质不育系对白背飞虱的抗性反应。试验结果表明,具有D型不育胞质的不育系国广5A明显抗白背飞虱。     

水稻光温敏核雄性不育系培矮64S 花粉败育的细胞学机理

 采用半薄切片及薄切片技术, 对水稻光温敏核雄性不育系培矮64S 与正常水稻品种IR36 的花粉形成发育过程进行了比较研究。结果表明, 小孢子母细胞减数分裂之前, 培矮64S 与IR36 的发育过程基本相似。但从减数分裂开始, 培矮64S 的雄性性细胞出现一些异常变化, 并最终发育至二胞花粉早期败育。这些变化主要发生在两个阶段: (1) 减数分裂前期,约半数的小孢子母细胞的胞质出现异常, 游离核糖体稀少, 并具有不发育线粒体和大量泡状内质网。这类异常的小孢子母细胞在随后的发育中逐渐液泡化并最终解体。(2) 早期小孢子形成之后, 几乎所有小孢子外壁均发育异常, 表层与里层之间界限不清, 缺少中间透明带, 同时内壁没有形成。但是, 在花粉发育的整个过程中, 培矮64S 与IR36 绒毡层的发育和降解过程基本相似。据此认为, 培矮64S 的花粉败育可能是由小孢子母细胞或花粉外壁的异常发育造成的, 而不是由绒毡层发育引起的。     

水稻空间诱变雄性不育新种质的细胞学研究

通过对空间诱变产生的雄性不育新种质WS-3-1 及其亲本特籼占13和一般品种IR36花粉形成发育过程的深入研究,发现WS-3-1 是一份无花粉型的雄性不育新种质,不育性稳定,不受光温条件影响。其败育机理是花药中层在小孢子母细胞早间期开始液泡化,过早降解,引起绒毡层过早退化,使绒毡层无法正常行使功能,导致小孢子母细胞粘连并在二分体时期解体,无法形成花粉。初步认为空间致变作用是明显的,会诱导一些特殊的变异。     

水稻KV型不育系细胞质效应的研究

 为了探索KV胞质的利用价值,用KVV41A、WAV41A、KV福伊A、WA福伊A与不同类型的恢复系配制18对组合,其F₁的六个农艺性状结果表明,两种不同胞质组合的农艺性状有明显差异,除个别组合少数性状外,总的趋势是KV型组合优于WA型组合。在相同细胞核遗传背景条件下,KV型胞质组合的杂种优势大于WA型胞质组合的杂种优势,这种效应是受细胞质支配的。通过内源激素检测进一步探明：KVV41A、WAV41A和V41B中的内源素IAA、GA_1+3+4+7含量有明显差异。V41B两种内源激素总含量最高,其次是KV型,最低的是WA型。V41B在整个幼穗发育过程中两种内源激素含量也是始终高于WAV41A和KVV41A,不育系的含量都较低,这可能是引起雄性不育的内因之一。而KVV41A中两种内源激素总含量和幼穗发育多数时段的含量介于WAV41A与V41B之间,可能是 KVV41A较WAV41A更容易被恢复的原因之一。     

24份水稻细胞质雄性不育系的SSR多态性分析

利用SSR标记技术对四川省及其它部分省区生产中主要使用的和新育成的24份水稻细胞质雄性不育系材料进行遗传多样性分析,从135对SSR引物中筛选出具有多态性的引物34对,共扩增出77个等位位点,平均每个引物的等位位点数为2.26个;多态信息含量（PIC）变化范围0.080～0.559,平均为0.254。根据24份细胞质雄性不育系的遗传相似系数矩阵做出树状图,聚类分析结果表明,目前在生产中应用的水稻细胞质雄性不育系遗传背景比较单一,不利于充分发挥水稻杂种优势利用潜力。     

我国三系杂交稻主要不育系的微卫星标记多样性和遗传结构分析

选取均匀分布在水稻12条染色体上的48对SSR引物,对28份我国杂交水稻主要不育系进行了多样性和遗传结构分析。 在所分析的48个位点中,多态性位点41个,多态性位点百分率（P）为85.4%;每1个位点平均等位基因数（A）为3.5,变幅2～6个;平均基因多样性指数（He）和平均多态性信息含量指数（PIC）分别为0.40和0.36。AMOVA分析表明,不育系遗传变异主要存在于各选育时期内,时期间的遗传变异仅占总变异的3.3%,且未达到显著水平。基于模型的遗传结构分析表明,我国三系杂交稻主要不育系多数含有相近血缘,背景单一。     

光照长度对三系杂交水稻不育系育性影响的研究

以珍汕97A、V20A、龙特浦A、博A为材料,通过暗室人工遮光处理,研究了它们的育性对光照长度的反应。试验结果表明,珍汕97A、V20A、博A在不同光照长度条件下,育性反应不同,龙特浦A的育性有明显反应,而且随着光照长度的增加,不育性愈好,呈幂函数关系。珍汕97A、V20A和博A没有明显的变化。     

Comparisons on Genetic Diversity among the Isonuclear-Alloplasmic Male Sterile Lines and Their Maintainer Lines in Rice

Four sets of rice isonuclear-alloplasmic lines including 16 male sterile lines and their maintainer lines were analyzed by using 91 pairs of SSR primers to study the genetic diversity of nuclear genome and their relative relationships. A total of 169 alleles were detected in the 16 lines, with a frequency of polymorphic loci of 53.85% and an average number of alleles per locus of 1.8, and the average gene diversity was 0.228. Four sets of the isonuclear-alloplasmic male sterile lines shared 146 identical alleles, corresponding to 86.39% of the total alleles; meanwhile, there are 23 different alleles among the tested materials, being 13.61% of the total alleles. On average, 78.70% identical alleles and 21.30% different alleles of the total alleles were detected between the isonuclear-alloplasmic male sterile lines and their maintainer lines. There were 53.85% identical alleles and 46.15% different alleles of the total alleles among the homozygous allonucleus male sterile lines. The fingerprints were established for some male sterile lines and maintainer lines. All the materials tested were divided into three groups at the 0.2 genetic distance based on the cluster analysis. Eight lines of Huanong A and Huayu A (including Huanong B and Huayu B) were in the first group, four lines of Kezhen A (including Kezhen B) in the second group, and four lines of Zhenshan 97A (including Zhenshan 97B) in the third group. For the isonuclear-alloplasmic male sterile lines, the similarity coefficient between Y (Yegong) type and WA (wild abortive) type or between CW (Raoping wild rice) and WA type reached 87-98%.     

水稻细胞质雄性不育系裂颖种子的穗上分布规律研究

对4个具有不同裂颖特性的水稻细胞质雄性不育系及其保持系的种子裂颖率和4个不育系种子裂颖粒在穗上的分布特点进行了研究。结果表明：保持系种子裂颖轻于不育系,不育系与相应保持系的种子裂颖率呈显著正相关。不育系种子裂颖与同穗颖花开放的迟早有关,开花迟,裂颖率高;强势穗裂颖轻于弱势穗;一次枝梗轻于二次枝梗;穗上部轻于中部,中部轻于下部;一次枝梗第6粒位裂颖最轻,第2粒位相对较重;强势粒轻于弱势粒。     

Development and Application of SCAR Markers for Discriminating Cytoplasmic Male Sterile Lines from Their Cognate Maintainer Lines in Indica Rice

The DNA fragments about 1 600 bp were amplified using random amplified polymorphism DNA (RAPD) primer OPA12 with the templates of mitochondrial DNA of Zhenshan 97A and Zhenshan 97B,and were sequenced.The nucleotide sequences and lengths of the fragments from Zhenshan 97A and Zhenshan 97B showed no difference.The precise length of the fragment was 1 588 bp.Sequence characterized amplification region (SCAR) primers were then developed to discriminate the cytoplasmic male sterile (CMS) lines and their maintainer lines.A specific 1 588 bp fragment could be amplified with SCAR primers,CHI19F2/CHI19R2 and CHI20F3/CHI23R3,in the mitochondrial DNA of Zhenshan 97A,but not Zhenshan 97B.Furthermore,the specific fragment could be also amplified from the total DNA from green leaf tissues of Zhenshan 97A with SCAR primers,but not Zhenshan 97B.With the corresponding primers,the specific fragment could also be amplified from the total DNA of green leaves of other two CMS lines with wild abortive type cytoplasm (CMS-WA),namely Zhenpin A and Tianfeng A,but not in their maintainer lines.Moreover,using total DNA as template,each of the four pairs of SCAR primers could also be used to amplify the 1 588 bp fragment in CMS-ID (Indonesia paddy type) line Ⅱ-32A,but not in II-32B,and the specific fragment was amplified from the DNA of both F1 and F2 seedlings of Shanyou 63.The results of detecting the genetic purity of a man-made mixture of the seeds of Zhenshan 97A using CHI20F3/CHI23R3 were completely consistent with the phenotypes.Taken together,these results indicated that the specific 1 588 bp-fragment amplified by CHI20F3/CHI23R3 was the unique amplification products of CMS mitochondrial DNA,and could be used to distinguish CMS-WA and CMS-ID lines from their corresponding maintainer lines at the seedling stage.     

New Temperature Sensitive Genic Male Sterile Lines with Better Outcrossing Ability for Production of Two-Line Hybrid Rice

An investigation was carried out with three newly developed temperature sensitive genic male sterile(TGMS) lines for their floral traits, seed production potential and outcrossing ability in ten cross combinations. In the TGMS lines, fertile pollens had an average diameter of 0.89 mm while the sterile pollens was with 0.02 mm diameter.TS-29-150 GY produced the biggest fertile pollens with 0.92 mm and other two lines produced relatively smaller pollens with 0.91 and 0.85 mm. Pollen fertility during the fertility reversion period was an average of 60.7%. TS-29-150 GY had the maximum of 66.9% spikelet fertility whereas other two lines(TNAU18S and TNAU60S) had relatively lower spikelet fertility of 27.8% and 26.7%, respectively.Average of 17.00 g of seed yield was obtained in the TGMS lines during the fertility reversion period. TS-29-150 GY had the highest value of 21.20 g of seed yield while TNAU18 S and TNAU60 S produced 16.6 g and13.2 g of seed yield, respectively. The low seed production ability of these three TGMS lines was attributed only to the environmental conditions prevailing during the period. All three TGMS lines had considerable outcrossing potential of 41.2%, 24.6% and 25.0%, respectively. The cross combinations viz.TNAU18S/IET21508(36 g/plant), TNAU18S/IET21044(13 g/plant), TNAU18S/IET21009(26.5 g/plant),TNAU60S/CB-09-106(26.2 g/plant), TNAU60S/IET21009(14 g/plant) and TS29-150-GY/DRR 3306(39.2g/plant) showed perfect synchronization with acceptable hybrid seed yield, indicating suitability of TGMS system under Indian condition. Based on the outcrossing related traits viz. panicle exertion, angle of glume opening, stigma length and pollen size, TNAU18 S was identified as the best, followed by TS-29-150 GY.     

Genetic Mechanism of Dominant Earliness in Kefeng A, a New Rice Cytoplasmic Male Sterile Line

Kefeng A is an early maturing indica cytoplasmic male sterile (CMS) line of rice. Combinations derived from Kefeng A and late maturing indica restorer lines showed dominant earliness to various extents. To understand the genetic basis of dominant earliness, the genotype of photoperiod-sensitive genes in Kefeng A was analyzed using a complete set of heading time near isogenic lines (NILs) EG0 to EG7, ER, LR, T65, T65Eb, T65Ebm, T65m, NIL(Hd1) and NIL(Hd4). Results indicated that Kefeng A contained two dominant photoperiod-sensitive alleles E1 and Se-1u on E1 and Se-1 loci, respectively, and the genotype of photoperiod-sensitivity genes for heading time in Kefeng A was E1E1e2e2E3E3Se-1uSe-1uEf-1Ef-1. Based on the detected heading time genotype, in combination with the heading time of Kefeng A and the early maturing phenomenon in its derived F1 hybrids, it is speculated that Kefeng A might carry a dominant inhibitor gene Su-E1 for the dominant photoperiod- sensitive gene E1, and a recessive inhibitor gene i-Se-1 for another dominant photoperiod-sensitive gene Se-1. The reason why F1 hybrids from Kefeng A exhibited early maturing was hereby analyzed and the breeding value of dominant earliness related genes in Kefeng A was discussed.