乐香202B早熟性的遗传分析与基因定位初探

品种生育期是水稻最重要的农艺性状之一,通过遗传育种方法改变品种的生育期,特别是缩短生育期．对水稻生产的发展具有重要意义。研究材料乐香202B是由乐山市农科所提供的早熟稳定性较好的品种．对其研究表明,乐香202B具显性早熟基因,经遗传分析表明,符合3:1分离比,且不具感光性及胞质效应。将该基因初步定位在染色体第2染色体短臂端,暂定名为Ef-2(x)。与微卫星标记RM279、RM154有连锁关系,遗传距离分别为13．5cM和8．9cM。该基因的定位为下一步的基因分离和克隆奠定了基础。     

红米色素着生位置及其基因定位

分别对红米和白米做了石蜡切片观察,其色素位于果皮和种皮中;并对红米水稻材料红宝石进行了遗传研究及基因定位。红宝石与白色水稻R272的杂交F1表现为红色,表明色素基因受显性基因控制;同时,其F2群体米色性状遗传分离规律符合3∶1的分离比例,表明红色米皮的性状受1对显性基因控制。利用R272/红宝石的F2群体和微卫星标记,将该基因定位在第7染色体上RM8006和RM21186两个标记之间,其遗传距离分别为4.0cM和2.1cM,在物理图上这两个标记的距离为1.7Mb,并将该基因初步命名为Red。     

一个水稻披叶突变体的遗传分析和基因定位

在杂交育种后代中,发现了一个叶片披垂的突变体,暂命名为dl(t).通过两年观察,表现稳定遗传.以该突变体为父本,Y2B和缙香2B分别为母本配制杂交组合,F2遗传分析表明,该披叶性状由一对隐性基因控制.利用突变体与Y2B杂交得到的F2代群体进行基因定位,发现dl(t)基因位于第3染色体短臂上标记RM6038和RM5347之间,遗传距离分别为3.99 cM和0.94 cM.进一步在两标记之间发展新的分子标记,将该基因定位在RM6038和RM7576之间,分别相距3.99 cM和0.47 cM,且与RM1324共分离.这一结果表明该基因可能与已报道的水稻披叶突变基因dl(drooping leaf)等位.但该披叶突变体除叶片表现披垂外,其他性状与所有已报道的dl等位基因都不同,特别是花器官性状发育正常,这显然与已有报道的dl等位基因不同.     

水稻褐飞虱抗性基因的初步定位

本文应用229对水稻SSR引物对来自野生稻的褐飞虱抗性基因进行定位,结果表明引物RM589和RM311在作图群体BC2F2中存在多态性.通过作图软件进行基因和分子标记位点的遗传连锁分析,褐飞虱抗性基因与引物RM589和RM311的遗传距离分别是9.8cM和11.9cM,并将其定位在第6染色体和第10染色体上.     

利用染色体单片段置换系对水稻芒性状的4个QTLs进行定位分析

本研究以籼稻品种9311为受体和粳稻品种日本晴为供体构建而成的95个染色体单片段置换系为材料,对芒长、芒分布特征以及有芒置换系产量相关因子进行了调查分析。结合2008年和2009年的调查结果,通过代换作图共鉴定出4个与芒有无相关的QTLs,分别位于水稻第1、第2、第5和第7染色体上。qAWN-1被定位在第1染色体RM472与RM1387之间,遗传距离为6.6cM;qAWN-2被定位在第2染色体RM5804与RM4472之间,遗传距离为7.4cM;qAWN-5被定位在第5染色体RM1024与RM2422之间,遗传距离为14.1cM;qAWN-7被定位在第7染色体RM192与RM11之间,遗传距离为33.5cM。本研究所检测到的QTLs可以为理想型无芒品种分子标记辅助育种提供理论依据。     

水稻显性矮秆基因D55的精细定位

为了改良水稻品种的株型,本研究利用来源于普通野生稻的矮秆突变体lb4d与栽培稻品种(系)187R、广恢998杂交产生的F2群体对显性矮秆基因D55进行了精细定位。结果发现,D55基因对水稻株高具有较强的矮化作用,表现为显性矮秆。在日本晴、广恢998、187R等不同的遗传背景条件下,D55基因造成水稻株高降低30%左右;利用水稻SSR标记引物,D55基因首先被定位在水稻第11号染色体上RM5704和RM202之间3.53 cM区域;为了进一步精细定位D55基因,参考水稻品种日本晴的基因组序列,在D55基因附近区域寻找插入缺失序列,在RM5704和RM202之间发展了4个插入缺失标记,利用这4个标记将D55基因精细定位在indel A-7和indelg-15之间的53.1 kb区域。本基因精细定位的结果为D55基因的图位克隆提供了帮助。     

水稻抗白叶枯病新基因Xa32（t）的鉴定和初步定位

通过多菌系接种鉴定及抗谱分析,并与目前国际上已知抗白叶枯病基因比较,证明在水稻抗源C4064中含有一个新的抗白叶枯病基因,暂命名为Xa32(t)。应用分离集团分析法(BSA),借助SSR和EST等分子标记,对该基因进行了分子标记定位。通过对F₂分离群体及F₃家系单株进行遗传连锁性检测,发现6个位于水稻第11染色体长臂末端的分子标记RM27256、RM27274、RM2064、ZCK24、RM6293和RM5926与Xa32(t)基因连锁。它们与Xa32(t)基因间的遗传距离分别为2.1、1.0、1.0、0.5、1.5和2.6 cM。其中标记RM6293和RM5926位于染色体近端粒一侧,其他4个标记RM27256、RM27274、RM2064和ZCK24位于基因的另一侧。将Xa32(t)定位在水稻第11染色体长臂末端2.0 cM范围内。     

水稻抗白叶枯病新基因Xα32(t)的鉴定和初步定位

通过多菌系接种鉴定及抗谱分析,并与目前国际上已知抗白叶枯病基因比较,证明在水稻抗源C4064中含有一个新的抗白叶枯病基因,暂命名为Xα32(t).应用分离集团分析法(BSA),借助SSR和EST等分子标记,对该基因进行了分子标记定位.通过对F2分离群体及F3家系单株进行遗传连锁性检测,发现6个位于水稻第11染色体长臂末端的分子标记RM27256、RM27274、RM2064、ZCK24、RM6293和RM5926与Xα32(t)基因连锁.它们与Xα32(t)基因间的遗传距离分别为2.1、1.0、1.0、O.5、1.5和2.6 cM.其中标记RM6293和RM5926位于染色体近端粒一侧,其他4个标记RM27256、RM27274、RM2064和ZCK24位于基因的另一侧.将Xα32(t)定位在水稻第11染色体长臂末端2.0 cM范围内.     

水稻抗白叶枯病新基因Xa32（t）的鉴定和初步定位

通过多菌系接种鉴定及抗谱分析,并与目前国际上已知抗白叶枯病基因比较,证明在水稻抗源C4064中含有一个新的抗白叶枯病基因,暂命名为Xa32(t)。应用分离集团分析法(BSA),借助SSR和EST等分子标记,对该基因进行了分子标记定位。通过对F₂分离群体及F₃家系单株进行遗传连锁性检测,发现6个位于水稻第11染色体长臂末端的分子标记RM27256、RM27274、RM2064、ZCK24、RM6293和RM5926与Xa32(t)基因连锁。它们与Xa32(t)基因间的遗传距离分别为2.1、1.0、1.0、0.5、1.5和2.6 cM。其中标记RM6293和RM5926位于染色体近端粒一侧,其他4个标记RM27256、RM27274、RM2064和ZCK24位于基因的另一侧。将Xa32(t)定位在水稻第11染色体长臂末端2.0 cM范围内。     

几个香稻保持系香味的遗传研究

对四川省新选育的7个香稻保持系和1个引进改良的香稻品种的香味遗传和等位性进行了分析,同时,利用微卫星DNA标记对D香2 B和泸香90的香味基因进行了初步定位.结果显示,所有香稻品系(品种)与非香稻杂交,F1植株的叶片均无香味,显示出香味由隐性基因控制;从香与香杂交F1植株、回交BC1F1和F2群体分析看,D香1 B、D香2 B、内香2 B、内香4 B、绵香2 B、绵香3 B、宜香1 B的香味受单隐性基因所控制;泸香90的香味可能受一对抑制基因和一对香味基因控制.初步将D香2 B和泸香90的香味基因定位在第八染色体上,D香2 B香味基因位点与SSR引物RM 210相距17.3 cM,与RM 515相距5.7 cM;泸香90的香味基因位点与RM 515相距4.3 cM.RM 515可应用于水稻分子育种实践.     

4份水稻早熟不育系配合力比较研究

品种生育期是水稻最重要的农艺性状之一,通过遗传育种方法改变品种的生育期,特别是缩短生育期,对水稻生产的发展具有重要意义。本研究对4份早熟不育系材料:D64A、乐香101A、乐香202A、早显A所配组的F1代产量构成性状进行配合力分析,结果表明:一般配合力和特殊配合力方差分析表明:乐香101A早显AD64A乐香202A;早熟性利用配组分析表明:乐香202A早显AD64A乐香101A。由此可见,乐香202A/B具备部分显性早熟主效基因,乐香101A/B、早显A/B、D64A/B具较高产量性状配合力,通过基因克隆、转基因等手段可有效将目前杂交早稻所存在的早熟性与丰产性之间的矛盾协调一致,最终培育出两者兼备的新品种。     

A new dominant earliness character of CMS line Zaoxian A and its application value in rice (Oryza sativa L.)

Summary A distant cross between a maintainer Zhenshan 97B and an early maturing F₂ palnt of O. longistaminata x O. rufipogon was made in 1985, and a new CMS line Zaoxian A was bred in 1989 through continuous backcross of new maintainer plants derived from the distant cross to the leading CMS line Zhenshan 97A. Several experiments were carried out in Sichuan during 1990–1992, to analyze the inheritance of earliness of Zaoxian A and its application value to hybrid rice production. The results showed that Zaoxian A was as early-maturing as Zhenshan 97A, the earliness of Zaoxian A was incompletely dominant to the lateness of restorer lines, and was different from the earliness of Zhenshan 97A which was suppressed by the lateness of restorer lines. The F₁ hybrids between Zaoxian A and late maturing restorers combined the early maturity and high yielding capacity, and significantly outyielded the provincial and national checks with same or longer growth duration, because the larger genetic distance between early and late maturing ecotypes remained unchanged and the new earliness could express in F₁ generation. Therefore, the new dominant earliness character of Zaoxian A could enhance the regional and seasonal adaptability of rice. It is also valuable to hybrid rice production and the formation of new cropping systems with high yielding capacity and high economical profit.     

甘蓝型油菜早熟性状QTL定位及候选基因筛选

目前对于油菜早熟的研究主要围绕开花期性状进行,虽然开花期与生育期呈显著正相关,但却并不完全一致。对于油菜开花后一系列生长发育进程相关性状的遗传研究和QTL定位鲜有报道。本研究以成熟期差异较大的2个油菜品种‘花前早’和‘Global’构建的DH群体为材料,对影响油菜全生育期的各个发育阶段(开花期、花期持续时间、角果期持续时间和全生育期等)进行表型调查和QTL定位分析。共检测到30个早熟相关性状QTL位点,其中开花期、花期持续时间、角果期持续时间和全生育期等分别检测到12、5、4和9个QTL位点,解释了5.8%~22.4%的表型方差。发现4、2和1个全生育期QTL置信区间分别与开花期、花期持续时间、角果期持续时间位点置信区间完全或部分重叠。筛选到29个可能与油菜早熟性状相关的候选基因,它们通过调控花期或籽粒发育等生长发育进程影响油菜早熟。因此,在早熟性状的研究中,可以同时从开花期和籽粒发育过程入手,不但有利于使熟期进一步提前,也可减缓早熟油菜品种过早开花导致的冬前低温寒潮天气的不利影响。     

Breeding for earliness in spinach (Spinacia oleracea L.) as based on environmental and genetic factors

Summary One of the most important characters of a spinach cultivar is its earliness. This is determined by the rate of bolting and so by the rate of flower formation, as both coincide almost completely. The rate of flower formation is determined by three factors: Daylength (photoperiodic) requirement. The 7 cultivars tested showed an increased rate of flower formation at longer photoperiods, early cultivars having a higher rate than late cultivars. Rate of growth. By varying the light intensity and temperature, the rate of flower formation appeared to be related to the rate of growth. An increase in the latter is usually accompanied by an increase in the former. So acceleration of growth results in earlier bolting. Balance between growth and development. Indian Thorny and Virtuosa, although having similar daylength requirements and rates of growth, differ in earliness, which is ascribed to a difference in energy distribution over the growth and development processes. Indian Thorny is thought to use more energy for development processes than Virtuosa does.The genetic control of earliness is most likely a polygenic one as rate of growth and balance between growth and development can be expected to be polygenically controlled. This also means that earliness and yield are linked to each other; selection for the one often results in selection for the other. To select for the required earliness without unwanted yield effects, or to increase yield without changing the earliness, selection methods have been described, which are directed to each of the three components individually.Also published as Publication 297 of the Laboratory of Horticulture.     

水稻两系不育系的育种应用分析

水稻是重庆市最重要的粮食作物,两系杂交水稻因育种效率高、制种成本低、品种稻米品质好等优势,近年来成为水稻研究的热点之一。为明确两系水稻杂交组合遗传特性,选择了渝优系列代表性恢复系11个,分别与两系不育系‘C815s’、‘深08s’配制两系杂交新组合,对新组合的农艺性状、产量性状及组合实际产量进行了分析。结果显示,‘C815s’组合在株高、产量、稻瘟病抗性等性状上优于‘深08s’组合,而‘深08s’组合则在生育期、有效穗、稻米品质等方面优于‘C815s’组合。研究结果为两系亲本的创制及两系新品种的选育提供了一定的参考价值。     

Genetic analysis of flowering and maturity time in high latitude spring wheat

Due to the short growing season in the high northern latitudes, the development of early maturing spring wheat (Triticum aestivum L.) cultivars is important to avoid frost damage which can lower production and quality. We investigated earliness of flowering and maturity, and some associated agronomic traits, using a set of randomly selected high northern latitude adapted spring wheat cultivars (differing in maturity) and their F₁ and F₂ crosses made in a one-way diallel mating design. The parents, and their F₁ and F₂ crosses were evaluated under field conditions over 2 years. Anthesis and maturity times were controlled by both vernalization response and earliness per se genes, mainly acting additively. Non-additive genetic effects were more important in controlling grain fill duration, grain yield and plant height. Additive × additive epistatic effects were detected for all traits studied except time to anthesis. Segregation analyses of the F₂ populations for time to anthesis indicated the presence of different vernalization response genes. Molecular genetic analyses revealed the presence of Vrn-A1 and Vrn-B1 genes in the parental cultivars. Narrow-sense heritability was medium to high (60–86%) for anthesis and maturity times but low to medium (13–55%) for grain fill duration, plant height and grain yield. Selection for early flowering/maturity in early segregating generations would be expected to result in genetic improvement towards earliness in high latitude spring wheats. Incorporation of the vernalization responsive gene Vrn-B1 in combination with vernalization non-responsive gene Vrn-A1 into spring wheats would aid in the development of early maturing cultivars with high grain yield potential for the high latitude wheat growing regions of the northern hemisphere.     

An Analysis of Grain Development in Oryza sativa L. Cultivars

A field study was conducted to determine if differences in grain filling rate and duration existed in two early cultivars of rice. There is no cultivar difference in duration of grain filling and grain matured in about 30 days from anthesis in both the cultivars. The effective grain filling period in rice is only 10 days between 3rd and 13th day from anthesis. There is significant difference in grain filling rate and is positively related to grain weight. Grain filling rate is more important than duration of filling for achieving higher grain size and thus yield in rice.     

土壤酸化对双季早、晚稻产量的影响

土壤pH是影响水稻生长的重要因素,目前还不清楚土壤酸化对双季水稻产量的影响。本研究利用硫酸调节土壤pH结合移栽后浇灌不同pH的水使土壤酸化。结果表明,随着土壤pH的下降,双季早、晚稻生育期延长,物质生产量下降,产量降低,当浇灌水pH下降至4.5以下,土壤pH下降至5.0以下时,双季早、晚稻产量下降明显,其中早稻平均下降7.82%,晚稻平均下降8.06%;当浇灌水pH下降至3.5以下,土壤pH下降至4.5以下时,双季早、晚稻产量下降幅度更大。土壤酸化主要抑制双季早、晚稻前期分蘖的发生,导致每穗粒数降低,结实率和千粒重也表现出下降的趋势。     

Measurement of response to vernalization in Australian wheats with winter habit

Summary Development in wheat is strongly controlled by sensitivity to vernalization and photoperiod, and to a lesser degree by non-vernalizing temperature and intrinsic earliness. A method to measure effect of vernalization in wheats with winter habit is described. Twenty seven wheats with winter habit and eight with spring/facultative habit were studied, comprising breeding lines and cultivars with maturities suited to south-central New South Wales. Effect of vernalization on the development of these wheats was quantified by integrating responses to vernalizing treatments of differing duration. Intrinsic earliness was measured as time for vernalized seedlings to grow to ear emergece in an 18h photoperiod with day/night temperature of 21/16°C, and response to photoperiod as the difference in time to ear emergence between 9 and 18h daylengths. Integrated response to vernalization is sensitive to both cumulative and thresh-hold responses and is applicable to wheats of all habit type. Integrated response to vernalization and intrinsic earliness were positively associated within wheats with winter habit. Wheats were largely of restricted origin, so that there were few allelic differences at Vrn loci to disrupt this association, which suggests intrinsic earliness may modify response to vernalization. Though integrated response to vernalization was measured with artificial treatments, it was strongly associated with ear emergence for wheats with winter habit when grown at a site in New South Wales.