粳稻穗角与谷粒性状的相关性及谷粒性状遗传分析

粳稻穗角小的品种产量高而品质差。谷粒性状与产量和品质都有关联。为培育产量与品质相协调的品种提供相关遗传信息,测定了粳稻直立穗品种丙8979和弯曲穗品种C堡及其重组自交系349个株系的穗角和7个谷粒性状,分析了穗角与谷粒性状之间的相关性,并运用主基因+多基因混合遗传模型,对7个谷粒性状进行了遗传分析。结果表明,穗角与粒厚、长厚比和宽厚比均无显著相关,而与千粒重、粒长、粒宽和长宽比均呈极显著正相关。7个谷粒性状均受2对主基因+多基因控制,2对主基因的作用方式因性状而异。千粒重、粒长、长厚比和宽厚比4个性状以主基因遗传为主;粒宽、粒厚和长宽比3个性状以多基因遗传为主。     

粳稻穗角与谷粒性状的相关性及谷粒性状遗传分析

粳稻穗角小的品种产量高而品质差。谷粒性状与产量和品质都有关联。为培育产量与品质相协调的品种提供相关遗传信息, 测定了粳稻直立穗品种丙8979和弯曲穗品种C堡及其重组自交系349个株系的穗角和7个谷粒性状, 分析了穗角与谷粒性状之间的相关性, 并运用主基因+多基因混合遗传模型, 对7个谷粒性状进行了遗传分析。结果表明, 穗角与粒厚、长厚比和宽厚比均无显著相关, 而与千粒重、粒长、粒宽和长宽比均呈极显著正相关。7个谷粒性状均受2对主基因+多基因控制, 2对主基因的作用方式因性状而异。千粒重、粒长、长厚比和宽厚比4个性状以主基因遗传为主; 粒宽、粒厚和长宽比3个性状以多基因遗传为主。     

粳稻穗部性状遗传分析

从粳稻(Oryza sativa ssp. japonica)RIL群体中选取每穗颖花数极端少的品系丙堡3201和丙堡3205及每穗颖花数极端多的品系丙堡3145和丙堡3214, 配制丙堡3201×丙堡3145和丙堡3214×丙堡3205两个组合的P₁、P₂、F₁、B₁、B₂和F₂ 6个世代, 调查每穗颖花数、每穗实粒数、穗长、一次枝梗数和二次枝梗数的表型分布, 并运用主基因+多基因混合遗传模型,对这5个性状进行了遗传分析。结果表明, 每穗颖花数性状在2个组合的各分离世代均未出现超亲分离, 而其它4个性状均有不同程度的超亲分离。一次枝梗数受1对主基因+多基因控制; 其余4个性状均受2对主基因+多基因控制。每穗颖花数、每穗实粒数、穗长和二次枝梗数4个性状以主基因遗传为主, 一次枝梗数性状以多基因遗传为主。     

粳稻穗部性状遗传分析

从粳稻（Oryzasativassp.japonica）RIL群体中选取每穗颖花数极端少的品系丙堡3201和丙堡3205及每穗颖花数极端多的品系丙堡3145和丙堡3214,配制丙堡3201×丙堡3145和丙堡3214×丙堡3205两个组合的P1、P2、F1、B1、B2和F26个世代,调查每穗颖花数、每穗实粒数、穗长、一次枝梗数和二次枝梗数的表型分布,并运用主基因＋多基因混合遗传模型,对这5个性状进行了遗传分析。结果表明,每穗颖花数性状在2个组合的各分离世代均未出现超亲分离,而其它4个性状均有不同程度的超亲分离。一次枝梗数受1对主基因＋多基因控制;其余4个性状均受2对主基因＋多基因控制。每穗颖花数、每穗实粒数、穗长和二次枝梗数4个性状以主基因遗传为主,一次枝梗数性状以多基因遗传为主。     

杂交粳稻及其亲本千粒重与产量、品质的相关性

为了探明杂交粳稻及其亲本千粒重与产量、品质的关系,以4个千粒重介于23.1~28.0 g之间的BT型不育系和24个千粒重介于18.1~32.0 g之间的三系粳稻恢复系,采用p×q不完全双列杂交(NCⅡ)设计,配制96个杂交组合为试验材料,对F1千粒重优势表现、F1千粒重与亲本千粒重及其与产量、品质性状间的相关性进行分析,确定高产优质兼顾的杂交粳稻的千粒重范围。结果表明:(1)56.3%的杂交组合千粒重超过其双亲平均值,19.8%的杂交组合千粒重表现正向超亲优势;(2)F1千粒重与母本千粒重、父本千粒重、双亲千粒重平均值的相关性均达极显著水平(r=0.33**、0.71**、0.78**),且恢复系千粒重对杂种的影响大于不育系;(3)F1千粒重、父本千粒重及双亲千粒重平均值与组合单株产量的相关性均达极显著水平(r=0.55**、0.47**、0.51**),母本千粒重与组合单株产量相关不显著;(4)F1千粒重、父本千粒重与糙米率、精米率、整精米率、垩白粒率、粒长、粒宽均呈极显著正相关,与透明度呈显著正相关,母本千粒重与垩白粒率、垩白度、粒长均呈极显著正相关,与粒宽呈显著正相关;(5)杂交粳稻育种中具有高产优质兼顾的F1千粒重范围应在25.1~27.0 g之间。     

籼型杂种稻米品质性状的数量遗传分析

应用新近提出的ｐ＾＋ｑ＾＋ｐｑ交配设计的种子性状遗传表达鉴别方法,分析了籼型水稻３个不育系和１０个恢复系配组的３０个杂种Ｆ１植株上的Ｆ２种子及其亲本的９个稻米品质性状。结果表明：（１）粒长、粒宽、粒重、糙米率和完整精米率５个性状在Ｆ２米粒间没有发生遗传分离,它们的遗传受二倍体母体基因型（Ｆ１植株）控制。（２）垩白率、直链淀粉含量、糊化温度和胶稠度４个性状则在Ｆ２米粒间有极显著的遗传分离,帮主要受三     

密穗型和散穗型粳稻品种品质特性比较

比较2个粳稻密穗型和散穗型品种(系)品质结果表明,穗型间和穗型内品质存在较大差异,2个密穗型品种(系)平均垩白特性不及2个散穗型品种.密穗型新品系EA6垩白粒率较相同穗型品种秀水63低约1/2,与散穗型品种秀水11相仿,较散穗型品种越光高约1倍;垩白度较秀水63和秀水11低约1/2,较越光高1倍多.调查穗部不同部位籽粒垩白表明,穗基部籽粒垩白对品种总垩白影响最大,而这种影响密穗型更大于散穗型.4个品种饭香味相仿,光泽、软度、粘度、食味和冷饭软度等指标EA6显著或极显著优于秀水11,秀水63不及秀水11;EA6多数指标接近越光.表明密穗型品种经改良其品质有可能达到甚至超过散穗型品种.     

云南高原粳稻品质特性分析

采用表型主成分及聚类分析法,对76个云南高原粳稻的11个品质性状进行了分析。结果表明,（1）直链淀粉含量的平均值达食用稻品种品质1级标准,糙米率、透明度、碱消值和胶稠度达2级标准,精米率达3级标准,其余品质性状的平均值均在3级以下。品种间变异最小的品质性状是糙米率和碱消值,变异最大的是垩白度,其次是垩白粒率。（2）稻米品质性状间存在复杂的相关关系。（3）在选出的6个影响云南稻米品质的主因子中,精米率、垩白粒率和垩白度因子对稻米品质的累积贡献率为49.6%。（4）76个云南粳稻聚为4类,其中第一类包括52个品种,表明遗传距离近,遗传基础狭窄。在今后的云南粳稻品质育种中,应降低垩白粒率和垩白度,提高精米率和整精米率,同时拓宽遗传基础。     

不同穗型粳稻品种产量和品质性状的比较分析

利用不同穗型粳稻品种,在不同氮肥水平下对产量性状和品质性状进行了比较.试验结果表明,随着施氮水平的提高,直立穗型品种产量增加幅度大于半直立和弯曲穗型品种,但产量构成因素的变化趋势,在各种穗型品种间变化基本一致.随着施氮量的增加,3种穗型品种的糙米率、精米率和整精米率均增加,而垩白率的变化在不同穗型品种间不相一致.直立穗型品种较半直立和弯曲穗型品种,胶稠度相对较硬,蛋白质含量较高,并且对氮素的反应较敏感.     

水稻单株有效穗数主基因＋多基因混合遗传分析

选择单株有效穗数差异大的3个亲本CB1（15.3）、CB4（6.4）和CB7（11.8）,配制CB1×CB4和CB7×CB4组合,建立了相应的P_1、F_1、P_2、B_1、B_2、F_2群体,将其分为中、晚两个生产季节种植,考察了有效穗数性状.利用主基因＋多基因混合遗传模型理论的Akaike信息准则（AIC）在B_1、B_2、F_2代中鉴定影响数量性状的主基因存在与否,主基因存在时通过分离分析估计主基因和微效基因的遗传效应及所占总变异的分量.结果表明该性状在所有B_1、B_2、F_2中均符合2对加性-显性-上位性主基因＋加性-显性-上位性多基因的遗传模式,主基因遗传率为30.64%-72.26%,多基因遗传率为3.41%-28.20%,总基因遗传率为45.96%-87.29%;相同组合种植季别主基因遗传率及一阶参数对比表明,杂交亲本的选择及种植季别对该性状遗传率影响较小,h_a、h_b、j_（ab）、j_（ba）值均为负值表明显性效应和加性显性互作对该性状表达具有抑制作用.     

Novel pleiotropic loci controlling panicle architecture across environments in japonica rice （Oryza sativa L.）

To identify quantitative trait loci (QTLs) controlling panicle architecture in japonica rice, a genetic map was constructed based on simple sequence repeat (SSR) markers and 254 recombinant inbred lines (RILs) derived from a cross between cultivars Xiushui 79 and C Bao. Seven panicle traits were investigated under three environments. Single marker analysis indicated that a total of 27 SSR markers were highly associated with panicle traits in all the three environments. Percentage of phenotypic variation explained by single locus varied from 2% to 35%. Based on the mixed linear model, a total of 40 additive QTLs for seven panicle traits were detected by composite interval mapping, explaining 1.2%-35% of phenotypic variation. Among the 9 QTLs with more than 10% of explained phenotypic variation, two QTLs were for the number of primary branches per panicle (NPB), two for panicle length (PL), two for spikelet density (SD), one for the number of secondary branches per panicle (NSB), one for secondary branch distribution density (SBD), and one for the number of spikelets per panicle (NS), respectively. qPLSD-9-1 and qPLSD-9-2 were novel pleiotropic loci, showing effects on PL and SD simultaneously. qPLSD-9-1 explained 34.7% of the phenotypic variation for PL and 25.4% of the phenotypic variation for SD, respec- tively. qPLSD-9-2 explained 34.9% and 24.4% of the phenotypic variation for PL and SD, respectively. The C Bao alleles at the both QTLs showed positive effects on PL, and the Xiushui 79 alleles at the both QTLs showed positive effects on SD. Genetic variation of panicle traits are mainly attributed to additive effects. QTL × environment interactions were not significant for additive QTLs and additive × additive QTL pairs.     

Limiting factors for panicle photosynthesis at the anthesis and grain filling stages in rice (Oryza sativa L.)

Panicle photosynthesis is crucial for grain yield in cereal crops; however, the limiting factors for panicle photosynthesis are poorly understood, greatly impeding improvement in this trait. In the present study, pot experiments were conducted to investigate the limiting factors for panicle photosynthesis at the anthesis stage in seven rice genotypes and to examine the temporal variations in photosynthesis during the grain filling stage in the Liangyou 287 genotype. At the anthesis stage, leaf and panicle photosynthesis was positively correlated with stomatal conductance and maximum carboxylation rate, which were in turn associated with hydraulic conductance and nitrogen content, respectively. Panicle hydraulic conductance was positively correlated with the area of bundle sheaths in the panicle neck. During grain filling, leaf and panicle photosynthesis remained constant at the early stage but dramatically decreased from 8 to 9 days after anthesis. The trends of variations in panicle photosynthesis were consistent with those in stomatal conductance but not with those in maximum carboxylation rate. At first, the maximum carboxylation rate and respiration rate in the panicle increased, through elevated panicle nitrogen content, but then drastically decreased, as a result of dehydration. The present study systematically investigated the limiting factors for panicle photosynthesis, which are vital for improving photosynthesis and crop yield.     

水稻核不育系4个柱头性状的遗传分析

为改良水稻(Oryza sativa)核不育系柱头性状提供遗传信息, 调查了粳型核不育系7001S、籼型核不育系Z913S及其杂交、自交获得的F₁、F₂和F_2:3群体的4个柱头性状, 分析了4个性状间的相关性, 并利用主基因+多基因遗传模型对2个世代4个性状进行遗传分析。结果表明, 4个性状两两间呈极显著正相关, 相关系数介于0.274-0.897之间。除F_2:3群体中花柱长度和柱头外露率分别表现出受2对加性-显性主基因和1对负等效加性-显性主基因+多基因控制外, F₂和F_2:3群体的柱头长度、花柱长度、柱头-花柱总长度以及柱头外露率均表现出受2对主基因和多基因控制, 且F_2:3群体中控制花柱长度的主基因表现出加性-显性效应, 其余均表现出加性-显性-上位性效应。2个世代中4个性状均以主基因遗传为主。     

Genetic studies of rice (Oryza sativa L.) anther culture response

Anthers of two rice (Oryza sativa L.) varieties, Lunhui 422 (P₁) and Jinzao 5 (P₂), their F₁, F₂ and first backcross generation-F₁ x Lunhui 422 (B₁), and F₁ x Jinzao 5 (B₂)-were cultured in L8 medium to study the inheritance of rice anther culturability using generation mean analysis. Significant effects of generation were observed for the four traits measured: anther response (%), frequency of callus induction (%), frequency of callus differentiation (%) and culture efficiency (%). Variation among the generations was similar for all traits: significant differences were found among six generations and the means of the P₂ and B₂ were significantly lower than those of the other generations. The frequency of callus differentiation showed a nonsignificant difference among the P₁, F₁, F₂ and B₁ generations which had slightly high values than the P₂ and B₂. Additive genetic variance (V_A) was higher than non-additive genetic variance (V_D) for anther response and frequency of callus induction. However, A_V was lower than V_D for frequence of callus differentiation and culture efficiency, V_A was significant for all traits except for the culture efficiency, and V_D was nonsignificant for all traits except for the frequency of callus differentiation. On the other hand, environmental variation (V_E) was significant for the 4 traits. Narrow-sense heritability estimates were 95.52%, 82.19% and 13.54% for anther response, frequency of callus induction and culture efficiency, respectively.Abbreviations 2,4-d 2,4-dichlorophenoxyacetic acid - IAA indole-3-acetic acid     

Genetic analysis of plant regeneration in rice (Oryza sativa L.)

Summary A diallel study involving reciprocal crosses of four genotypes (IR8, 36, 54, and 64) was carried out to understand the genetic mechanism of plant regeneration from immature embryo-calli in rice. Regeneration frequency (% of calli that produced plants) varied from a high of 86% for IR54 to a low of 0% for IR36, while regenerated plants per embryo numbered from 0 to 7 when these same IR lines and the F₁ hybrids were compared. Combining ability analysis revealed that both nuclear (with both additive and dominant effects) and cytoplasmic genes are important in controlling regeneration in rice. Parental lines and F1 hybrids with high ability to regenerate were identified.     

水稻微卫星标记的发展和应用

微卫星又称简单序列重复。它是由几个核苷酸（一般２～４个）为重复单位组成的串联重复序列。相同座位上的重复序列由于重复次数的不同而造成序列长度的多态性。微卫星标记是一种共显性标记,具有等位基因丰富、检测技术简单等优点。微卫星标记在基因组作图、品种鉴定、种质保存、分子标记辅助选择等方面有着广泛的应用。目前水稻中已发展了３００多个微卫星标记。     

Association mapping for yield and grain quality traits in rice (Oryza sativa L.)

Association analysis was applied to a panel of accessions of Embrapa Rice Core Collection (ERiCC) with 86 SSR and field data from two experiments. A clear subdivision between lowland and upland accessions was apparent, thereby indicating the presence of population structure. Thirty-two accessions with admixed ancestry were identified through structure analysis, these being discarded from association analysis, thus leaving 210 accessions subdivided into two panels. The association of yield and grain-quality traits with SSR was undertaken with a mixed linear model, with markers and subpopulation as fixed factors, and kinship matrix as a random factor. Eight markers from the two appraised panels showed significant association with four different traits, although only one (RM190) maintained the marker-trait association across years and cultivation. The significant association detected between amylose content and RM190 was in agreement with previous QTL analyses in the literature. Herein, the feasibility of undertaking association analysis in conjunction with germplasm characterization was demonstrated, even when considering low marker density. The high linkage disequilibrium expected in rice lines and cultivars facilitates the detection of marker-trait associations for implementing marker assisted selection, and the mining of alleles related to important traits in germplasm.     

水稻穗型突变体cl的鉴定、保护与遗传分析

通过神州八号飞船搭载广东省常规优质稻主导品种粤农丝苗获得一个稳定遗传的穗型突变体cl,中文名为粤花占1号,2015年完成农业部植物新品种权的申请工作(申请号:20151728.8,公告号:CNA014491E)。该突变体农艺性状与野生型极为相似,熟色好,产量高,但表现出异常的花序结构,一次枝梗数增加,二次枝梗、小穗梗长度严重缩短,枝梗顶端小穗3粒簇生在一起。进一步的细胞学观测发现,差异主要源自幼穗分化的第3期到第4期发育异常所致。遗传分析表明该性状由非完全显性单基因控制,BSA性状定位法初步将该基因定位于染色体6,命名为CL-6。本研究的结果为进一步精细定位和克隆CL-6基因、找到控制水稻幼穗枝梗伸长缩短的功能基因或调控因子奠定基础,同时为培育理想穗型水稻和观赏农业提供优良种质。     

雌雄同株黄瓜单性结实性主基因+多基因混合遗传分析

以雌雄同株黄瓜强单性结实自交系'6457'和非单性结实自交系'6426'为亲本,建立了5世代联合群体(P1、P2、F1、F2、F2∶3),采用植物数量性状主基因+多基因混合遗传模型对群体的单性结实性进行多世代联合分析.结果表明:雌雄同株黄瓜单性结实性表现为不完全显性遗传,符合D-2遗传模型,受1对加性主基因+加性-显性多基因控制.主基因加性效应值为14.7,多基因加性效应值为20.9,多基因显性效应值为25.8.F2的遗传率为56.6%,F2∶3的遗传率为48.7%.因此,对雌雄同株黄瓜单性结实性的遗传改良,可选择强单性结实性材料,通过杂交、回交转移主基因,达到选育强单性结实性材料目的.