水稻落粒性及相关基因克隆研究进展

种子落粒性的丧失是水稻驯化的关键特征之一，不仅减少了产量损失，还提高了收获效率。文章综述了近年来水稻落粒性的研究进展，包括水稻落粒性及形成的生理基础、调控落粒性的基因定位与克隆以及在驯化过程中落粒性的变化，以期深化对水稻驯化和落粒调控机制的研究，为水稻育种方向提供新的思考，推动水稻种植业发展。     

水稻落粒基因SH8的精细定位与克隆

落粒性是水稻的重要性状之一,是野生稻种子传播和后代繁衍的重要保障,但是容易落粒在栽培稻的生产中会造成产量损失。目前,在水稻中已经克隆了一些落粒相关基因,但是这些基因并不能解释水稻落粒的全部表型变异。本研究从白谷(Pei-kuh)和普通野生稻(W1944)构建的重组自交系中选取落粒性强且不含有SH4基因的材料E6-5,与Pei-kuh进行杂交构建分离群体,将以前检测到位于8号染色体的落粒QTL精细定位于26.4 kb的区间内,并把该位点的落粒基因命名为SHATTERING8(SH8)。该区段共有4个编码基因,Pei-kuh和E6-5的测序比对发现LOC＿Os08g41950基因在编码区有3个碱基的差异,同时实时定量PCR分析表明该基因在离层部位表达,因此我们把LOC＿Os08g41950作为SH8的目标候选基因。为了验证LOC＿Os08g41950是否参与水稻落粒的调控,我们利用来自E6-5的LOC＿Os08g41950编码序列构建了过表达载体并遗传转化Pei-huh。落粒表型鉴定结果表明,与Pei-huh相比,转基因植株的落粒性明显增强,不仅种子脱落所需的拉力值显著降低,而且还具有更光...     

一个水稻落粒性基因SH1的SSR标记定位

以籼稻品种93-11为轮回亲本,与粳稻品种日本晴杂交并回交的高世代分离群体为研究材料,选用104个多态性的SSR标记对水稻的落粒性基因进行定位。结果表明,在BC₄F₂群体中,6个标记的基因型来自于日本晴;在BC₄F₃定位群体中,难落粒植株数与易落粒植株数的分离比例为3:1,落粒性受1对显性基因控制,命名为SH1;分子标记与落粒性共分离分析将SH1定位在SSR标记RM5389和RM1068、RM1387之间,与3个标记的遗传距离分别为0.7cM、5.5cM和13.1cM,此结果为该基因的分子标记辅助选择奠定了基础。     

水稻稻瘟病抗性基因定位、克隆及应用

稻瘟病是水稻生产中最严重的病害之一,严重影响水稻的产量和品质,由于稻瘟菌小种的变异快,垂直抗性基因难以持续控制稻瘟病的危害,因此,定位和克隆广谱持久的稻瘟病抗性基因,揭示其作用的分子机理,结合分子育种技术培育高产优质多抗的水稻新品种将是今后解决稻瘟病抗性育种最有效的途径.本文综述了水稻和稻瘟病菌之间的互作,稻瘟病抗性的分子机制,稻瘟病抗性基因定位,目前已经定位了73个稻瘟病质量抗性基因,其中9个稻瘟病抗性基因已经被克隆并进行了深入的研究,此外定位了至少11个QTL以及稻瘟病抗性基因克隆和功能分析,及其在水稻抗病育种中的应用.     

水稻抽穗期基因研究进展

抽穗期是水稻品种的重要农艺性状之一,它对于水稻适应不同的栽培地区和耕作季节是至关重要的。近年来,在水稻抽穗期基因的发掘、定位、克隆及作用机制等方面,特别是QTL研究方面取得较大进展。在此,回顾了水稻抽穗期基因/QTL的定位和克隆,阐述QTL的互作及与主基因的等位性关系,并通过和拟南芥模式植物的对比进一步阐述了水稻开花的分子机制,为研究禾本科植物的抽穗期基因提供了有意义的启示。旨在为中国水稻抽穗期基因遗传以及在育种上的应用提供理论依据。     

水稻落粒性基因qSH1调控区关键SNP的HRM检测体系优化

高分辨率熔解曲线(high resolution melting,HRM)分析是一种新发展起的DNA多态性快速筛查分析技术,具有灵敏、准确和高效等突出优势。q SH1是控制水稻落粒性的主效基因,在该基因的上游12 kb的调节区存在一个SNP位点(命名为q SH1(G/T))调控其表达,从而引起不同品种间落粒性差异。为针对q SH1(G/T)位点建立一种HRM快速分型检测体系,本研究以难落粒的粳稻品种"日本晴"和易落粒的"R1128"为材料,研究了不同的PCR产物长度、DNA浓度、Mg2+浓度、退火温度及扩增模式对HRM分型效果的影响。结果表明:使用q SH1-1引物(产物长度68 bp)能获得平稳的熔解曲线和单一熔解峰;当DNA浓度在5 ng/μL以上、退火温度为60℃、Mg2+浓度为1.5 mmol/L时,HRM分型效果最佳;此外,选择降落PCR模式能取得较好的分型效果。研究结果可为后续该位点的基因分型及水稻落粒性分子遗传改良的研究奠定基础。     

水稻粒型、粒重和灌浆研究进展

水稻(Oryza sativa L.)是全球主要粮食作物之一,挖掘水稻中产量相关性状的数量性状位点(quantitative trait loci, QTL),对提高水稻产量、保障国家粮食安全具有重要作用。构成水稻产量的三个要素包括单株有效穗数、每穗粒数及千粒重。其中千粒重遗传力为40%～60%,遗传稳定,受外界环境因素影响较小。因此,提高粒重来确保水稻产量是一条有效途径。水稻千粒重与粒型密切相关,水稻粒型性状由粒长、粒宽和粒厚共同构成。此外,千粒重不仅取决于籽粒库容量(粒型)也取决于其充实度(灌浆)。因此,研究水稻粒型和粒重与灌浆速率对于提高水稻产量和改良水稻品质均有重要作用。本研究总结了水稻粒型、粒重和灌浆已定位和克隆的基因研究进展,为水稻的籽粒性状育种提供参考。     

水稻稻瘟病抗性基因的定位、克隆及育种应用研究进展

稻瘟病是一种世界性的水稻病害,抗病品种的培育和种植是控制该病害最为经济有效的方法,而抗病基因的发掘与利用则是抗病育种的基础和核心。本研究就稻瘟病抗病基因的遗传、定位、克隆及育种应用情况进行了概述,介绍了稻瘟病广谱抗原和抗病基因、隐性抗病基因研究的最新进展,指出近一半的抗病基因是通过F2分离群体鉴定的,目前已定位的稻瘟病主效抗病基因超过86个,微效基因约350个,应用图位克隆等方法,20个稻瘟病主效抗病基因和2个微效基因已从不同的水稻品种中被克隆。这些基因的定位和克隆是有效开展稻瘟病抗性分子育种的基础。最后,结合笔者从事水稻稻瘟病抗性遗传的工作实践对稻瘟病抗病基因研究存在的问题进行了分析和展望,相信随着越来越多各类型抗性基因的生产应用,稻瘟病对水稻的危害最终能得到有效的控制。     

水稻抗稻瘟病基因的克隆及其分子育种研究进展

由子囊菌Magnaporthe oryzae引起的稻瘟病一直是困扰水稻生产的难题。克隆水稻抗稻瘟病基因并通过分子育种手段培育抗性品种是防治稻瘟病最经济有效的方法。本文主要综述了国内外抗稻瘟病水稻品种资源的发掘现状,讨论抗稻瘟病基因的定位、克隆及其连锁标记研究进展,并描述了已克隆的水稻抗稻瘟病基因在染色体上的分布特点、等位性特征、结构特点以及作用方式,并对目前国内外通过分子标记辅助培育抗稻瘟病水稻品种的应用现状进行展望。     

水稻长穗颈基因eui的研究与利用

eui基因作为"杂交稻种子生产的第四遗传要素",二十多年来,备受国内外遗传育种学者的关注.最近,关于水稻穗颈伸长基因EUI的定位与克隆、功能鉴定及eui基因在水稻育种中的应用取得了较大的进展.本文概述了长穗颈基因eui的发现、定位与克隆、作用机制及其在水稻育种中的应用.     

贵州禾落粒性基因qSH1调控区SNP分析

贵州禾是在贵州省黔东南地区种植的一类特殊的稻种,为探究其遗传特性,本研究对49份贵州禾和来源中国11个省市(自治区)和韩日的112份稻种的落粒性基因qSH1调节区序列进行测序分析.结果 表明,161份供试品种在696个碱基序列上存在13个变异位点,归为6种DNA单倍型,在功能位点12 290上,仅H6为T,属不易落粒单...     

Effect of quantitative trait loci for seed shattering on abscission layer formation in Asian wild rice Oryza rufipogon

Asian cultivated rice Oryza sativa L. was domesticated from its wild ancestor, O. rufipogon. During domestication, the cultivated rice lost its seed-shattering behaviour. Previous studies have shown that two major quantitative trait loci (QTLs; qSH1 and sh4) are responsible for the seed-shattering degree. Here, we produced introgression lines carrying non-functional alleles from O. sativa ‘Nipponbare’ at the two major QTLs in the genetic background of wild rice O. rufipogon W630, and examined the effects of the two QTLs on seed shattering and abscission layer formation. The introgression lines, with Nipponbare alleles at either or both loci, showed complete or partial abscission layer formation, respectively, indicating that other unknown loci might be involved in enhancing seed shattering in wild rice. We detected a single QTL named qSH3 regulating seed-shattering degree using an F₂ population between Nipponbare and the introgression line carrying Nipponbare alleles at the two QTLs. Although we generated an introgression line for qSH3 alone, no effects on seed shattering were observed. However, a significant effect on seed-shattering degree was observed for the introgression line carrying Nipponbare alleles at qSH3 and the two QTLs, suggesting an important role of qSH3 on seed shattering in coordination with the two QTLs.     

Seed Shattering of Cañahua (Chenopodium pallidicaule Aellen)

Cañahua (Chenopodium pallidicaule Aellen) is a semi‐domesticated relative of quinoa (Chenopodium quinoa Willd.) with high nutritious quality. It is tolerant to frost, drought, saline soils and pests. One seed yield limitation is seed loss during the maturity stages. Two greenhouse experiments in Denmark and field experiments in Bolivia were carried out to determine seed shattering in landraces and cultivars with different growth habits. 15–21 % of the seed shattering in the fields took place whilst the plants still were flowering and 25–35 % during physiological maturity. Seed shattering varied between locations on the Bolivian Altiplano. Cañahua types with the semi‐prostrate growth (‘lasta’) had the highest seed shattering rate in the greenhouse experiments. The Umacutama landrace had lower seed shattering (1 %) than the cultivar Kullaca (7.2 %) both of the ‘lasta’ type. Under field conditions, the cultivar Illimani with the erect growth (‘saihua’) had the highest seed shattering rate (6.4–33.7 %) at both locations and at four different sowing dates. The Umacutama had the lowest rate (0.5–1.5 %). There were no significant differences between plants of the ‘lasta’ and the ‘saihua’ types. The landrace had significantly less seed loss than the cultivars. However, in the greenhouse, the landrace yield was approximately 25 % lower than the yields of the cultivars. In general, cañahua cultivars had higher yield compared to landraces, but also a higher seed shattering rate. Landraces may be used in breeding programmes to develop high‐yielding cultivars with reduced seed shattering.     

广东湛江杂草稻qSH1基因片段序列分析

摘要：为了探讨杂草稻与栽培稻在qSH1基因片段是否存在差异。利用已经报道的扩增水稻qSH1基因的引物,对来源于广东湛江雷州地区的6份落粒性非常强的杂草稻进行PCR检测,通过测序得到约460bp的核苷酸碱基序列,序列分析结果表明：该核苷酸碱基序列大致位于qSH1基因下游100kb处,与NCBI网站公布的核苷酸序列为同源序列,同源性达100 %。这6份杂草稻与水稻之间共同存在一个碱基位点差异,经证实正是前人报道的SNP位点。另外6份杂草稻所获片段序列不完全一致,存在一个位点差异,但不能确定是否为一个作用位点。     

中等落粒性的改良型超级稻‘协青早A/M9308’应用价值评价

为了改善超级稻组合‘协青早A/T9308’易落粒特性,达到延长其生产应用寿命之目的,利用γ射线诱变技术,从易落粒恢复系T9308（显性）中,筛选到难落粒突变体M9308（隐性）,并配制出具中等落粒性F1组合‘协青早A/M9308’。采用分期播种方式,再次对M9308、T9308、‘协青早A/M9308’和‘协青早A/T9308’在整个抽穗、灌浆和成熟等重要时期的落粒性、产量性状和稻米品质性状进行观察研究,并对‘协青早A/M9308’和‘协青早A/T9308’的2008-2009年多点大区自然和机割落粒损失作了调查。结果表明,M9308难落粒特性表达稳定,不论所处环境或成熟度大小,其落粒率均极显著低于T9308;‘协青早A/M9308’落粒性与其他协优系列相近,明显低于‘协青早A/T9308’;‘协青早A/M9308’和‘协青早A/T9308’的农艺性状、经济性状与稻米品质性状均相仿;‘协青早A/M9308’明显减少了田间自然和机割稻谷损失率。综上所述,该改良型‘协青早A/M9308’具有替代原超级稻‘协青早A/T9308’而获得生产上可持续应用的实用价值。     

The genetic correlation of panicle shattering with the intact rachilla form of seed retention in Phalaris aquatica L.

Panicle shattering and seed retention are distinct characters that influence seed dispersal in Phalaris aquatica L.(phalaris). One form of seed retention in phalaris is the result of the thickening of the rachilla (intact rachilla) and disruption of the rachilla-break age mechanism. This form of seed retention results in seed dispersal as seed-retaining panicle fragments, providing an opportunity to reduce ant predation of seed, and thereby increase the potential for seedling recruitment. A genetic analysis of panicle shattering and the intact rachilla form of seed retention was conducted on parental clones and derived half-sib families of across between the seed retaining cultivar Atlas PG and the non-seed retaining cultivar Sirocco, grown as spaced plants over two seasons in the field. A simulation of panicle shattering of the parents and families was also devised under glasshouse conditions. The narrow-sense heritability of panicle shattering in the field was 51 ± 10% and 58 ± 12%,on the basis of half-sib family means and parent-offspring regression, respectively,and its genetic correlation with panicle shattering under simulated conditions was24 ± 8%. The narrow-sense heritability of the intact rachilla form of seed retention was 70 ± 17% on a half-sib family mean basis. Seed retention had a negative genetic correlation of 71 ± 19% with panicle shattering, posing a difficulty for breeding seed-retaining cultivars with readily shattering panicles. However, it was considered likely that the two traits were controlled by independent sets of genes and that this association could be broken. This association is discussed in the context of breeding cultivars with seed dispersal characteristics that promote seedling recruitment under conditions of ant predation of the seed bank. This revised version was published online in August 2006 with corrections to the Cover Date.     

A source of resistance to seed shattering in kleingrass,Panicum coloratum L.

Summary Seed of kleingrass, P. coloratum, ripen nonuniformly and shatter readily at maturity. Consequently, it is difficult to maximize both seed quality and yield. A source of resistance to seed shattering is needed. In this investigation, two kleingrass populations, the cultivar Selection-75, and an introduction from South Africa, PI 410177, were evaluated for seed shattering during three seed production seasons. Individual inflorescences from field-grown plants were enclosed in seed traps and all shattered seed was collected at weekly intervals until 49 days after anthesis. Although there were seasonal differences, PI 410177 always shattered seed at a slower rate than Selection-75 in each of the three seasons. Averaged over all seasons Selection-75 had shattered 74% of its seed by 49 days after anthesis while PI 410177 shattered only 37%. A separate greenhouse-field experiment demonstrated that seasonal differences in seed shattering are primarily the result of varying weather conditions during the period of seed production. PI 410177 is the first reported source of resistance to seed shattering in P. coloratum.     

Traits of shattering resistant buckwheat ‘W/SK86GF’

Seed shattering is a significant problem with buckwheat, especially at harvesting time. Several reports have shown that a green-flower mutant of buckwheat, such as W/SK86GF, has a strong pedicel. Although a strong pedicel may provide some resistance to shattering in the field, no study has thoroughly examined this issue. In this paper, we demonstrate that a W/SK86GF has shattering resistance by comparing the degrees of shattering of W/SK86GF and Kitawasesoba (leading variety of Hokkaido with non-green-flower traits) through a test for four years, including a typhoon hit year in the field. In a non-typhoon year, the shattering seed ratio (shattering seed weight/(yield + shattering seed weight) × 100) of W/SK86GF at maturing time +15 days (+15D) was lower than that of Kitawasesoba. In a typhoon hit year, the shattering seed ratios of Kitawasesoba at maturing time and +15D were surprisingly high, 14.4 and 21.1%, respectively. On the other hand, those of W/SK86GF were only 3.08% and 2.57%, respectively; indicating W/SK86GF is promising as a shattering resistant line even in a typhoon hit year. From these results, shattering resistance of W/SK86GF can be evaluated after maturing time such as +15D and pedicel strength would confer W/SK86GF a shattering resistant trait.     

不同收获时期对油菜机械收获损失率及籽粒品质的影响

以华油杂62为材料,测定70%油菜角果变黄至角果明显炸裂时期机械收获的产量损失、植株不同部位水分含量、粒重和籽粒含油量等指标,研究不同收c获时期对产量损失率和籽粒品质的影响。试验表明,机械收获的产量总损失率在7.00%~15.80%之间,随着收获时期逐渐推迟,总损失率先降低后增加。产量损失分为自然脱粒损失、割台损失和清选脱粒损失。割台损失率随收获时期推迟逐渐增加,占总损失率的比例为7.80%~31.01%;清选和脱粒损失率随收获时期推迟逐渐降低,是机械收获中最大的损失部分,占总损失率的56.87%~92.20%。总损失率与籽粒、角果皮、主花序和分枝水分含量均呈极显著正相关。籽粒水分含量为16.23%时千粒重和含油率最高,而后,随籽粒水分含量的下降,千粒重、含油率、全碳含量和C/N值均略有降低。油菜机械化收获以籽粒和角果皮水分含量在11%~13%之间时为宜,此期的千粒重、油分含量、机械收获产量和产油量均较高。