提高光敏感雄性不育水稻花粉单倍体育种效率及不育花粉植株育性转换特点的研究

比较了(光敏s/正常品种)F_1及F_2为供体亲本,对在花药培养时所获得的花粉植株中不育个体/全部花粉植株之比例的影响。结果表明,以F_1为供体亲本,在所获得的二倍体花粉植株(A_1)中,不育株(长日下)约占20%左右;而从F_2分离的不育株为供体亲本,相应的比例为90%左右。对获得不育的花粉植株而言,供体亲本经过F_2的选择,在花粉一代中可以提高育种效率3—4倍。指出,以培育光敏感雄性不育系为目的的花药培养,与一般育种之花药培养采用杂种F_1为供体亲本不同,不仅应对杂种F_2代在长日照条件下进行不育株的选择,而且应在短日照下对这种不育株作育性转换的双重选择。以这种个体作为花药培养的供体亲本,可以大大提高育种效率。 在长日照下表现不育的花粉植株的育性转换具多样性。来自同一组合的不育花粉植株在晚造(短日照)条件下,其花粉有的染色,频率高且稳定;有的虽然可变为染色,但频率不高或不稳定或二者兼有;有些却一直不为Ⅰ-KⅠ染色,或即使染色频率也在10%以下。这一结果与收集全国各地15个光敏核不育系在本昕同期种值条件下的反应十分吻合。这说明通过花药培养,从特定的组合培育出所需要的光敏/光温互作或温敏型的核不育系的可能性是存在的。     

提高光敏感雄性不育水稻花粉单倍体育种效率及不育花粉植株育性转换特点的研

比较了（光敏 s/正常品种）F1及F2为供体亲本,对在花药培养时所获得的花粉植株中不育个体／全部花粉植株之比例的影响,结果表明,以F1为供体亲本,在所获得的二倍体花粉植株（A1）中,不育株（长日下）约占20％左右;而从F2分离的不育株为供体亲本,相应的比例为90％左右,对获得不育的花粉植株而言,供体亲本经过F2的选择,在花粉一代中可以提高育种效率3－4倍,指出,以培育光敏感雄性不育系为目的的花药培养,与一般育种之花药培养采用杂种F1为供体亲本不同,不仅应对杂种F2代在长日照条件下不育株的选择,而且应在短日照下对这种不育株作育性转换的双重选择,以这种个体作为花药培养的供体亲本,可以大大提高育种效率。在长日照下表现不育的花粉植株的育性转换具仍多样性,来自同一组合的不育花粉植株在晚造（短日照）条件下,其花粉有的染色,频率高且稳定;有的虽然可变 染色,但频率不高或不稳定或二者兼有;有些却一直不I－KI染色,或即使染色频率也在10％以下,这一结果与收集全国各地15个光敏核不育系在本所同期种植条件下的反应十分吻合,这说明通过花药培养,从特定的组合培育出所需要的光敏／光温互作或温敏型的核不育系的可能性是存在的。     

感光性的遗传背景对水稻短光诱导雄性不育特性表达的影响研究

通过对双亲及Ｆ１的感光性分析和Ｆ２群体单株的感光性及短光不育特性分析表明,强感光性对弱感光性表现为显性;具短光不育特性的单株其感光性均表现为中度以上感光（短日出穗促进率〉１５％）。对宜ＤＩＳ与宜Ｄ２Ｓ的光敏性、感光性分析和不育基因的等位性测定表明,两者感光性与光敏性符合正相关的结论,它们的不育主基因是等位的。可以认为,对短光低温不育水稻,短光不育基因需要在感光性基因存在时才能得到表达,同一不育基因     

光敏感雄性不育水稻的体细胞与花药培养及再生植株性状表现研究

对8个光敏感雄性不育籼稻杂种一代及其亲本花药培养的研究发现,光敏不育粳稻虽然为雄性不育,但其愈伤组织诱导率与植株再生能力不在一般正常粳稻品种之下,为籼稻“新会粘”的28倍。绝大多数光敏不育之籼粳杂种的花药培养能力也是十分高的。在起源于体细胞及花药的光敏不育水稻之再生植株共1146株试管苗中,发现少数在5月下旬及6月上旬抽穗的已表现为完全雄性不育。这些材料之幼穗的第二枝梗分化时(4月下旬至5月上旬)之日长尚不足13小时,远在农垦58S的临界日长14小时之下。在8个组合的籼粳光敏杂种一代花粉植株中,有的组合完全表现为粳型(组合4及7,表2),有的完全表现为籼型(组合2及6),多数则两者兼有。在全部80个愈伤无性系中,单倍体20个,二倍体58个,多倍体2个。58个二倍体无性系申不育的为20个,占34.5%。其中在晚造短日照条件下能转变为可育的有11个,占二倍体的19%,占二倍体不育的55%。所有光敏不育花粉植株,在早造条件下I-KI之花粉染色率与结实率均为0%,在晚造(9月份之后)条件下,能转换为可育。但不同组合、不同无性系之间育性转换的频率与稳定性差异颇大。     

光（温）敏核雄性不育水稻的光周期与温度反应特性及其发育遗传规律

籼型光（温）敏不育稻均为温敏不育系,它们与粳型光敏不育稻结实的最适温度范围均较狭,两者的雄性细胞均较脆弱易受异常温度及长光为害,花药中有蛋白质组分不能转译,光敏不育性与感光性不能分开;光敏不育性的遗传是由2对独立的隐性不育基因控制,与其对应的2对恢复基因在粳稻、籼稻和爪哇稻中普遍存在,部分常规稻中原已存在1对隐性不育基因,农垦58S产生于农垦58一个基因位点的隐性光敏突变,控制农垦58S不育的2对隐性基因中来源于农垦58的1对即为与BT型水稻等位的不育基因。     

湖北光敏感核不育水稻不育性的遗传规律

本文选用5个常规粳稻品种和3小光敏感核不育系与湖北光敏感核不育水稻农垦58S杂交,用花粉育性、套袋自交结实率、自然结实率和大田目测4种育性指标同时鉴定同一植株育性,观察分析杂种后代在长日下植株育性的表现。结果表明：光敏核不育水稻不育性的遗传行为表现为受1对隐性主基因控制,不同的遗传背景对不育性的遗传行为表现有不同程度的影响。     

光敏核不育水稻农垦58S与正常品种“农垦58”在pmsl区段无育性基因分离

光敏核不育水稻农垦58S系由正常品种“农垦58”(Oryza sativa L.ssp.japonica)自然突变产生。为弄清该突变基因在染色体上的位置,曾用覆盖整个水稻基因组的300余个RFLP探针对农垦58S和“农垦58”进行了对比分析,得到了7个具多态性的探针,其中2个探针RG30和RZ626正好落在第7染色体上以前定位的光敏核不育基因pmsl所在的区段。以这两个标记对农垦58S/“农垦58”组合F_2随机群体140单株进行了RFLP分析,按RFLP基因型分组对育性作方差分析,结果表明,这2个标记位点与此群体中引起育性分离的位点无连锁关系。说明由正常“农垦58”变为光敏核不育农垦58S的突变基因不在pmsl区段。     

在控制条件下对不同稻种日长和温度反应发育特性的研究

本试验对153个不同栽培稻种在人工气候室的不同温度(20℃,25℃,30℃每日光长均为10小时),不同光照长度(每日10,12,13,14,18小时,温度均为25℃)控制条件下,观察了各品种抽穗结实等情况表明:品种间感光性有明显差异;早稻感光性大都较弱或中等,其中早籼大部分在长光下抽穗反早,属长日性;早粳一般在长光照下延迟抽穗;中稻感光性有弱、中、强三类,品种间差异大,个别品种在12～14小时抽穗快,属中间性;晚稻感光性大都较强,少数中等,最适光长为10～12小时。感温性同样有明显差异,早稻有中、强;中稻有弱、中、强三类,差异大;晚稻仅有中、强二类。早、中、晚稻的大部分品种最适温度均为25℃,少数南方品种及早、中稻为30℃。基本营养生长性在早稻品种内大部为弱及中,个别较强;中稻、晚稻也均有弱、中、强三类。全部供试品种的光,温反应类型共有20种。试验中还考查了81个品种在20℃、25℃下的结实情况,37个品种在30℃下的结实情况,有的品种较耐低温,有的较耐高温。作者还讨论了品种的光、温反应类型问题并指出新的类型将会继续随着科学的发展与生产的需要不断发现或创造出来。对籼,粳稻发育特性的区别及其形成与各该品种原产地的生态条件有不可分割的关系问题,指出原产南方的短日性水稻经过长期驯化、选育除了短日性     

水稻光(温)敏核不育系与核质互作不育系的遗传关系剖析

1991─1992年,分析了7个光(温)敏核不育系与15 个核质互作不育系杂交F1及部分F2植株在长日照和短日照条件下的育性表现,结果清楚地表明,有些光敏核不育系能够保持核质互作不育系的雄性不育性,有些光(温)敏核不育系则能够恢复或部分恢复; 有些光敏核不育系对某一核质互作不育系具有保持能力,对另一核质互作不育系则具有恢复能力; 并初步推测光(温)敏核不育基因与核质互作不育基因是独立发生的,当核质互作不育系中细胞质和细胞核的隐性不育基因一起作用时,能够掩盖光(温)敏不育基因及其育性恢复基因的表达。     

冬小麦杂种后代(F_1、F_2)早熟性遗传的初步分析

通过试验说明,小麦的早熟性属数量性状。用生育期不同的亲本杂交,F_1抽穗期介于双亲之间,并倾向早熟亲本;F_1杂种的平均优势为-14.2％;F_2的抽穗期呈连续变异,并出现超亲遗传现象。小麦抽穗期的遗传力较高,平均为63.76％。F_1的抽穗期与双亲抽穗期的平均值具有明显的相关性,r=0.767,回归系数为0.715。生育期不同的亲本对杂种后代有较大的影响。一般组合受“早亲”的影响较大,但也不能忽视“晚亲”的制约作用。不同亲本早熟性的遗传传递力不同。在育种工作中应注意早熟亲本的选择。根据早熟性遗传规律,可以“早中选早”,也可以“晚中选早”,在杂种的早期世代选择早熟的类型是有效的。     

一种紫色水稻的遗传及其在光敏不育系育种中应用的研究

研究表明,本院获得的一种紫色水稻的植株色遗传受控于C、 A、Pl3个独立基因座位上显性基因的互补作用,另有一独立的显性基因对Pl基因的表达起抑制作用。由于该抑制基因在籼稻中的高频率存在,因而,紫稻与一般绿稻品种杂交F1多表现为绿株。紫稻光敏不育(株)系的不育性表达和配合力表现,均可达到与普通光敏不育系相似的水平。本文还讨论了选育籼型紫稻光敏不育系设想的可行性。 Abstract:The inheritance of a purple rice in crosses to green rices was investigated.A group of dominant and interactive genes,C,A and Pl,was found to control the expression of the trait and the other independent inhibitor I-Pl-1 to inhibit the effect of the gene Pl.Because of the wide existence of the gene I-Pl-1 in indica rice,most of F1 plants of the crosses between purple rice and green cultivars were green.The primary study indicated that,for the purple photoperiod-sensitive genic male-sterile lines,the degrees of the sterility and its stability in the sterile stage,and of the fertility in the fertile stage,and the combining ability levels of the purple rice were as high as the degrees and levels for the green rice.A tentative idea on breeding purple photoperiod-sensitive male-sterile lines of indica rice was suggested and its feasibility and advantage was discussed.     

Cytological observation of two environmental genic male-sterile lines of rice.

We report here two environmental genic male-sterilities (EGMS) in rice. These two EGMS rice lines, thermo-sensitive genic male-sterility (TGMS) and photoperiod-sensitive genic male-sterility (PGMS), are controlled by temperature and photoperiod, respectively, in determining their male-sterility. Male-sterility of the TGMS and PGMS was found to be induced when they were grown at 32 degrees C/26 degrees C (day/night) with 14 h daylight, while they were fertile at 26 degrees C/20 degrees C (day/night) with 10 h daylight in a growth chamber. We also examined their anther structures under a light microscope. The light microscopic observation revealed that the EGMS lines showed a complete pollen abortion at the sterile growth condition while they produced normal fertile pollens at the fertile growth condition.     

Effect of End-of-day far-red light exposures on fertility alteration and flowering in photoperiod-sensitive genic male-sterile rice

The rice photoperiod-sensitive genic male-sterile mutant (PGMR) is sterile under long days, but fertile in short days. Phytochrome is involved in the photoperiod-induced male-sterile process. To investigate the mechanisms, of phytochrome action in PGMR, end-of-day (EOD) experiments were carried out. Flowering in PGMR was delayed considerably by EOD far-red light exposures following a short day of 10 hr, whereas its fertility decreased to the same extent as the original line. This result suggests that photoperiod response mediating fertility alteration in PGMR somewhat differed from that in flowering,i.e., fertility alteration and flowering might be under the separate phytochrome signaling control.     

Genotyping the Heading Date of Male-Sterile Rice Line Ⅱ-32A

Ⅱ-32A, an elite male-sterile line of rice (Oryza sativa L.), has been widely used for the production of hybrid rice seed in China. Heading date in most combinations using Ⅱ-32A shows transgressive inheritance or similarity to the latter parent, but the genotype of Ⅱ-32A with respect to major genes for heading time is unknown. This limits the further exploitation of this sterile line in breeding and hybrid seed production. Using a number of major gene heading date isogenic lines and heading date QTL near-isogenic lines, we genetically analyzed Ⅱ-32B under both long- and short-day conditions. We show that Ⅱ-32B carries two photoperiod-sensitive genes, E1 and E3, a recessive late-heading gene, ef-1, and a photoperiod-sensitive allele, Se-1u. In addition we identified in Ⅱ-32B a recessive inhibitor for E1 or Se-1n and other modified photoperiod-sensitive genes. The heading-date constitution of Ⅱ-32A was determined to be E1e2E3Se-1Uef-1i-Se-1.     

光敏核不育水稻开花和育性转变不同的光反应

从光敏核不育水稻"农垦585"幼穗分化至二次枝梗期开始,在每天的短日照光期（10h日光）结束、暗期开始时（EOD）进行15d的远红光（FR）照射实验,以比较开花、育性转变过程对短暂的远红光（FR）或红光（R）的反应。EODFR明显抑制水稻植株开花（穗分化）,导致"农垦585"和原种"农垦58"的抽穗期均比短日照下推退7d,表现为长日照效应,而"农垦58S"的结实率与原种相比却无显著变化。这暗示诱导农垦58S开花、育性转变过程的光反应可能有差异,前者不仅与光周期有关,且受EODFR的剧烈影响,而育性主要受光周期（临界暗期）控制,基本上不受EODFR的调控。     

Fertility response to photoperiod and temperature in indica photoperiod-sensitive male sterile rice

The aim of this work was to develop a photoperiod-sensitive male sterile rice with stable sterility. We developed Changguang S, an indica rice strain, by using a short critical day length. Differences in the fertility responses of Changguang S strain pollen to temperature and photoperiod under natural and controlled conditions were studied. The results showed that Changguang S strain exhibited stable sterility under long-day and low-temperature conditions (22°C, 15 days). The stability of sterility was significantly higher than that of other such rice strains, Nongken 58S and 7001S. The critical photoperiod for inducing male sterility in Changguang S was 13 h or shorter, and its duration was significantly shorter than that required for rice strains Nongken 58S and 7001S. It is suggested that Changguang S is a typical photoperiod-sensitive male sterile rice strain with a shorter critical day length and a lower critical temperature. It is promising to apply this strain to two-line hybrid rice production.     

Aanlysis of short photo-periodic sensitive genic male sterility and molecular mapping of rpms3(t) gene in rice (Oryza sativa L.) using SSR markers

A research was conducted on the pollen fertility of rice sterile lines D52S and D38S responsive to photoperiod during the sensitive stage under natural and controlled conditions. Bulk segregant analysis (BSA) and recessive class approach were applied to identify DNA markers that co-segregate with gene conferring male-sterility in D52S mutant rice. The results showed that in day-light higher or equal to 14.00 h, D52S and D38S rice pollen were fertile; however, they were sterile when day-length was less than 14.00 h. They were therefore considered to be short photo-periodic sensitive genic male sterile lines(Short PGMS lines). Under short day-light conditions, the pollen fertility segregation of F₂ populations from crosses between D52S/Shuhui527 and D52S/Gui99showed 3:1 ratio of fertile to sterile plants suggestingthat male sterility in D52S was controlled by one recessive gene. Two markers RM244 and RM216 located on chromosome number 10 co-segregated completely with the rpms locus. The locus was mapped to the interval between SSR markers RM2571 (6.6 cM) and RM244 (4.6 cM).