水稻雄性不育恢复系明恢63的感光基因分析

水稻恢复系明恢63是中国应用面积最大、利用最广泛的恢复系。利用抽穗期感光性近等基因系EG0～EG7及ER～LR对明恢63进行的分析表明,明恢63在E1、E2、E3位点分别带有E1、e3、E3基因,在Se-1位点带无感光功能的Se-1^e基因。进一步用抽穗期QTL近等基因系NIL(Hd1)和NIL（Hd4)进行的研究表明,明恢63带有显性感光基因E1和无感光功能的Se-1^e基因,并推测明恢63带有能抑制E,基因表达的隐性抑制基因。认为籼型杂交稻抽穗期受不育系和恢复系感光基因及感光性抑制基因的共同作用。初步讨论了明恢63广适性的遗传基础。     

水稻光温敏雄性不育系培矮64S的抽穗期基因型分析

利用抽穗期感光性近等基因系EG0—EG7、ER—LR及T65-T65m对培矮64S抽穗期基因型进行分析表明,培矮64S在E1、E、E3位点分别带有E1、e2、E3基因,在Se-1位点带无感光功能的Se-1^e基因,在Ef位点带有显性早熟基因Ef-1。进一步用抽穗期QTL近等基因系NIL(Hd1)和NIL(Hd4)进行的研究证实,培矮64S带有显性感光基因E1和无感光功能的Se-1^e基因。同时,用QTL近等基因系日本晴和NIL(Hd2)-NIL(Hd8)研究表明培矮64S带有能抑制E1基因表达的隐性感光抑制基因i-Se-1。文中对培矮64S广适性的遗传基础也进行了讨论。     

水稻品种USSR5早熟性的遗传分析

USSR5为极早熟的前苏联品种,以抽穗期近等基因系和抽穗期QTL近等基因系为测验品种,对USSR5的抽穗期基因型进行分析,表明USSR5携带了非感光基因e1、无感光功能的Se-1e基因、感光抑制基因i-Se-1和显性早熟基因Ef-1,从而使它表现极早熟的特性。此外,本研究调查了USSR5和N22的BC1F1和F2群体的抽穗期,利用WindowsQTLCartographer1.13a软件,采用复合区间作图法,在全基因组范围内,分析了南京夏季正常日照条件下2个群体的抽穗期QTL,在USSR5/N22//USSR5BC1F1群体,共检测到2个位点,分别位于第7、8染色体上,其LOD值分别是6.11和2.91,对表型总变异的解释率分别为27.38%和11.15%,2个位点上来自USSR5的等位基因均提早抽穗。在USSR5/N22F2群体,共检测到5个位点,分别位于第1、2、7、9、10染色体上。5个位点LOD值介于3.02～8.4,对表型总变异的解释率分别为4.07%和15.41%。除qHd-9外,其余控制抽穗期的4个基因位点上提早抽穗的等位基因均来源于USSR5。比较分析发现效应较大的qHd-7即是Hd4(E1),USSR5在该位点上携带非感光基因hd4(e1)。尽管本研究定位的其它抽穗期QTL和已知抽穗期基因之间尚不能一一对应,但在早熟性水稻品种选育中,USSR5将可作为良好的基因源加以利用。     

水稻株高和抽穗期基因的定位和分离

利用241个重组自交系构成的群体,对水稻（Oryza sativaL.)株高和抽穗期进行基因定位,三年共定位到4个抽穗期的数量性状基因（QTLs)和4个株高OTLs,其中位于第7染色体C1023-R1440区间的QTL3年均可检测到,且效应大,同时影响株高和抽穗期。为了区分这个区间的QTL是一因多效还是紧密连锁的两个QTLs,从自交系群体里选取QTL区间来自明恢63,其他遗传背景与珍汕97高度相似的自交系RⅡ50,与珍汕97回交,获得含有363个单株的近等基因系BC1F2群体。考察株高和抽穗期。两个性状在群体里表现为双峰分布,它们的分离比符合期望的单基因盂德尔遗传分离比,BC1E2群体单株的株高和抽穗期基本表现为矮秆早抽穗,高秆迟抽穗,但是,6个单株表现相反的情况,以上结果证明,QTL能够作为盂德尔因子进行研究,在BC1F2群体里,株高和抽穗期是由单个基因控制的,第7染色体上是两个紧密连锁的基因分别控制株高和抽穗期。     

水稻籼粳杂交胚囊败育的遗传分析和基因定位

利用DH系构建的分子图谱及DH系衍生的2个回交群体定位了引起籼粳杂种胚囊败育的2个互补的主效基因esa-1(E1或e1位点)和esa-2(E2或e2位点),它们分别位于第6和第12染色体.在不育基因位点,籼稻基因型为E1E1e2e2,粳稻基因型为e1e1E2E2,杂交后代中基因型为E1E2,E1e2,e1E2的雌配子体正常发育,携带e1e2基因型的雌配子体表现败育.胚囊育性受配子体基因型控制,孢子体遗传背景影响胚囊败育基因的表达.     

运用AFLP技术筛选分离野败型水稻mtDNA中与雄性不育性状相关的片段

对野败型水稻不育系（珍汕97A）、保持系（珍汕97B）和F1杂种（汕优63）线粒体DNA进行了AFLP比较,从M／PA引物对选择扩增产物中找到了不育系与保持系差异条带ZA1、ZA2和ZA3。Northern分析表明,片段ZA1黄化苗期无转录产物,可能是非编码序列;而ZA2、ZA3两片段在不育系、保持系和F1杂种中的转录则有差异,其中片段ZA2在黄化苗期保持系转录,不育系和F1杂种无转录产物;片段ZA3在黄化苗期保持系和F1杂种转录,表明ZA3转录受核恢复基因Rf影响．     

利用两种方法构建的近等基因系对水稻两个多效区段遗传效应进行评价

水稻每穗颖花数是水稻产量的重要构成因子之一。适当的抽穗期和株高对水稻高产是非常必要的。依据珍汕97和HR5衍生的重组自交系初步定位的结果, 利用高世代回交的方法构建了第7染色体同时控制抽穗期、株高和每穗颖花数的靶区段近等基因系(BC4F2); 利用基于重组自交系群体的杂合区段自交的方法构建了第8染色体同时控制抽穗期、株高和每穗颖花数的靶区段近等基因系, 并利用两个近等基因系对这两个多效区段的遗传效应进行了准确的评价。两个近等基因系的QTL分析结果表明, 3个性状都是由一个QTL或紧密连锁的QTL控制, 而且加性效应和显性效应的方向均相同; 同时3个性状在各自的近等基因系中呈现典型的双峰分布或不连续分布,这些结果暗示3个性状可能是一因多效的结果。文章还对抽穗期和株高与水稻产量的关系、3个性状显著正相关在育种中的应用及两种构建近等基因系方法的优缺点也进行了讨论。     

细胞质雄性不育水稻幼穗和花粉发育期的蛋白酶活性变化

水稻细胞质雄性不育系珍汕97A,在花粉母细胞形成期以后可溶性蛋白含量迅速降低。单核期仅为花粉母细胞形成期的56％,二核期和三核期分别为花粉母细胞形成期的36．4％和30．3％。保持系珍汕97B虽在花粉母细胞形成期后可溶性蛋白含量降低,但在二核期则有所增高,表现为鞍形变化过程。在花粉母细胞形成期后,珍汕97A的酪蛋白水解酶活性增高,单核期为前一时期的1倍,而珍汕97B的酶活性增幅较小。第一次枝梗分化期珍汕97A的内肽酶活性较珍汕97B高,而雌雄蕊形成期两者的酶活皆降低。整个发育期中珍汕97A的内肽酶活性较珍汕97B高15％至55．5％。珍汕97A在幼穗第一次枝梗分化期时氨肽酶活性较珍汕97B高。第二次枝梗分化期后,不育系和保持系的氨肽酶活性均下降。但花粉母细胞形成期后,珍汕97A的氨肽酶活性迅速增高,三核期达最高水平,这可能意味着此时大量蛋白质被水解。蛋白酶类抑制剂的实验表明,在雌雄蕊形成期后不育系和保持系含有半胱氨酸型氨肽酶和约10％含金属型氨肽酶;而在三核期,保持系的氨肽酶则主要为半胱氨酸型。不育系三核期含有的BAPA内肽酶包括半胱氨酸型、丝氨酸型,以及部分含金属酶类;而保持系三核期的内肽酶仅为丝氨酸型。不育系肽酶类型的变化,可能反映酶基因编码的去抑制。     

水稻配子体、孢子体细胞质雄性不育系线粒体蛋白质的分析

利用SDS-聚丙烯酰胺凝胶电泳方法分析了水稻配子体细胞质雄性不育系粤泰A、保持系粤泰B、F_1代泰优2号、恢复系胜优2号和孢子体细胞质雄性不育系马协A、保持系马协B、F_1代马协63、恢复系明恢63及另一种孢子体细胞质雄性不育系珍汕97A、保持系珍汕97B、F_1代汕优63、恢复系明恢63黄化苗的线粒体蛋白质。结果表明,粤泰A、B、F_1、恢复系之间出现6条多肽带的差异,马协A、B、F_1、恢复系之间出现4条多肽带的差异,珍汕97A、B、F_1、恢复系之间出现2条多肽带的差异。     

普通野生稻中增产相关QTL的发掘

普通野生稻(Oryza Rufipogon)是重要的遗传资源,发掘其优良等位基因将对水稻遗传改良产生重要影响。文章从以珍汕97为轮回亲本,普通野生稻为供体的BC2F1群体中选择一个与珍汕97表型明显不同的单株BC2F1-15,经过连续自交获得回交重组自交系BC2F5群体。均匀分布于12条染色体的126个多态性SSR(Simplesequence repeats)标记基因型分析,发现BC2F1-15单株在30%的标记位点为杂合基因型;利用该群体共检测到4个抽穗期、3个株高、4个每穗颖花数、2个千粒重和1个单株产量QTL。在第7染色体RM481-RM2区间,检测到抽穗期、每穗颖花数和产量QTL,野生稻等位基因表现增效作用;其他3个每穗颖花数QTL位点,野生稻等位基因也均具有增效作用。结果表明野生稻携带有增产相关的等位基因,这些有利等位基因无疑是水稻遗传改良可资利用的新资源。     

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.     

Pleiotropism of the Photoperiod-Insensitive Allele of Hd1 on Heading Date,Plant Height and Yield Traits in Rice

Five populations segregated in isogenic backgrounds and three sets of near isogenic lines (NILs) overlapping in a 362.3-kb region covering heading date gene Hd1 were developed from the indica rice cross Zhenshan97 (ZS97)/Milyang 46 (MY46). They were used to analyze the effects of Hd1 on heading date, plant height and yield traits. In a background of the parental mixtures, the photoperiod-sensitive allele derived from ZS97 functioned in promoting and delaying flowering in the natural short-day and long-day conditions, respectively. In the background of ZS97, no response to the photoperiod was observed, whereas the photoperiod-insensitive allele derived from MY46 functioned in delaying flowering, increasing plant height, and enhancing grain productivity. The additive effects estimated in two NIL sets were 6.14 and 6.14 d for heading date, 4.46 and 5.55 cm for plant height, 10.82 and 11.54 for the number of spikelets per panicle, 6.82 and 8.00 for the number of grains per panicle, and 2.16 and 2.23 g for grain yield per plant, which explained 94.1% and 96.3%, 70.5% and 84.8%, 52.4% and 55.2%, 28.9% and 39.2%, and 36.5% and 26.9% of the phenotypic variances, respectively. Since the photoperiod-insensitive allele of Hd1 confers a long vegetative phase, it is a good candidate for breeding rice varieties with high yielding potential for low latitudes.     

Mapping and Isolation of Quantitative Trait Loci Controlling Plant Height and Heading Date in Rice

Quantitative trait loci (QTL) were identified for heading date and plant height in rice ( Oryza sativa L.) using a recombinant inbred line population consisting of 241 lines. Totally 4 QTLs for heading date and 4 QTLs for plant height were detected in three years. The QTL with large effects located in the interval C1023-R1440 on chromosome 7 was simultaneously detected in three years for both traits. In order to distinguished the interval whether contained one QTL with pleiotropy effect or two close linked QTLs, a recombinant line RIL50, whose genetic background was high similar to Zhenshan 97 except the regions covered the major QTL from Minghui 63, was selected to cross with Zhenshan 97. A BC1F2 population from the cross, which could be regarded as near isogenic lines (NIL) with the targeted QTL (QTL-NIL), was used to collect heading date and plant height data. The frequency distribution of the two traits in the BC1F2 population was bimodal, and their segregation ratios were in accordance with the expected Mendelian inheritance ratios. Normally, the short plants flowered early in the population, the high plants with late heading date, but the relationships between the plant height and the heading date of 6 plants conflicted with the case. The above results clearly demonstrated that QTL could be treated as single Mendelian factor. Moreover, there are two close linked genes controlling the heading date and the plant height on chromosome 7, respectively.     

Differential Response of Floret Opening in Male-Sterile and Male-Fertile Rices to Methy Jasmonate

Effects of methyl jasmonate (MeJA) on floret opening were investigated in male-sterile and male-fertile rice ( Oryza sativa subsp. indica ). Excised or intact panicles with several top florets flowered one day before the experiments were soaked in MeJA, salicylic acid (SA), 24-epibrassinolide (24-epiBL) or control solution for 2 min. MeJA at the concentration of 4 mmol/L significantly promoted rice floret opening; the response of floret opening of male-sterile rice to MeJA was more sensitive than that of male-fertile rice (such as maintenance line and conventional variety). The percentage of finally opened-floret per panicle of Zhenshan 97A (cytoplasmic male sterile line) or Pei'ai 64S (thermo-sensitive genic male sterile line) treated with MeJA was over 40% in the day of experiment, that of Zhenshan 97B (maintenance) and Pei'ai 64 (conventional variety) was (21±1.5)% and (25±2.1)%, respectively; floret opening of intact Pei'ai 64S panicles in the field could also be induced by 2-mmol/L MeJA. The percentage of opened floret in all control panicles was 0% or less than 5% in the day of experiment. The percentage of fertilized-grain of Zhenshan 97A and Longtepu A could be increased over 24% by spraying panicles with 2-mmol/L MeJA solution （circa 6.0 μmol per panicle）. The lag time (time from the finishing of treatment to first floret opening) of male sterile line responsing to MeJA was 10 min shorter than that of male fertile line. MeJA induction on the rice floret opening could markedly be inhibited by SA solution at the concentration of 1 mmol/L, and the inhibition of SA on MeJA induction on floret opening of male-sterile rice could be nullified by MeJA treatment again. MeJA effect on floret opening of male-sterile rice could be clearly synergized by pretreatment with 24-epibrassinolide (24-epiBL).     

细胞质雄性不育水稻幼穗和花药的呼吸酶活性研究

研究珍汕97A和珍汕97B的雌雄蕊原基形成期、花粉母细胞形成期和花粉母细胞减数分裂期的幼穗及单核期、二核期和三核期的花药中呼吸代谢三羧酸循环（TCA）的苹果酸脱氢酶（MDH）和异柠檬酸脱氢酶（IDH）及戊糖途径（PPP）的磷酸葡萄糖脱氢酶（G6PDH）、磷酸葡萄糖酸脱氢酶（6PGDH）和5一磷酸核糖异构酶（RSPI）的活性。结果表明：可育花药的5种酶活性皆高于同期不育花药;而幼穗中,TCA途径中的MDH和IDH在不育系与保持系之间无差异,PPP途径的G6PDH和6PGDH及R5PI则保持系高于不育系。这说明不育系中PPP发生的变化早于TCA途径,PPP途径的改变可能与小孢子败育有着更为直接的关系。     

Genotypes of Heading Date of Middle Indica Rice in the Mid-lower Region of the Yangtze River

Middle indica cultivars are planted in the middle to lower regions of the Yangtze River. Hybrid combinations with these cultivars have a high yield potential but the presence of late-transgressive-segregants limits the further exploitation of heterosis. To understand the genetic basis of the heading date in these middle maturing cultivars, we carried out a genetic analysis of 10 typical middle-season cultivars using a number of heading date isogenic lines under both long and short day conditions. The results showed that Teqing, 752, CDR22, Bo B, 9311 and 11-32B carry two photoperiod sensitive genes E1 or Se.1 and E3, and Teqing, 752 and CDR22 carry a dominant early-heading gene Ef-1 while Bo B, 9311 and 11-32B carry a recessive late-heading gene ef-1. Based on the findings of the present and previous works on Guichao 2, Minghui 63, Nanjing 11 and Pei＇ai64S, it was concluded that all of these middle indica cultivars carried the recessive allele hd2, which could inhibit the expression of El or Se.1, and they formed rational combinations of genotype for heading date during a long period of evolution. The effects of the different combinations of genotype for heading date on rice cultivation and extension were discussed, and genetic basis of broad adaptability of hybrid middle indica cultivars was analyzed.     

水稻雄性不育与花药中类脂褐素的积累

细胞质雄性不育水稻不育系珍汕９７Ａ和其保持系珍汕９７Ｂ,处于不育期的光（温）敏核不育水稻Ｗ６１５４ｓ和培矮６４ｓ的花药中类脂褐素（ＬＦＬＰ）含量随花粉发育或败育而增高．不育花药中ＬＦＬＰ的形成速率比可育花药快,三核期的珍汕９７Ａ和不育期Ｗ６１５４ｓ的花药,其ＬＦＬＰ比相应具育性花药高２４％．用抗氧化剂ＧＳＨ、ＢＨＴ和Ｎ２处理离体的单核期花药,发现ＧＳＨ可降低珍汕９７Ａ和不育期的Ｗ６１５４ｓ的ＬＦＬＰ含量．结果认为,水稻雄性不育与膜脂过氧化作用的荧光产物类脂褐素的积累有关．