不同环境条件甘蓝型油菜含油量钝感系数的QTL分析

本研究以甘蓝型油菜GH06和中油821为亲本杂交,后代通过＂一粒传法＂连续自交8代构建重组自交系群体SWU-2为材料,利用本实验室已构建的遗传连锁图谱和复合区间作图法（CIM）对三个不同环境下含油量及含油量环境钝感系数进行QTL分析。结果表明：（1）不同环境中共检测到49个含油量相关QTL分别位于10个不同连锁群上,单个QTL可解释3.31%~12.47%的表型变异,42个含油量环境钝感系数QTL分别位于12个不同连锁群上,单个QTL可解释表型变异的4.05%~14.68%;（2）7个含油量相关的QTL与含油量钝感系数QTL相互重叠,分别位于第1、5、8、10、15和20连锁群上。研究结果表明明甘蓝型油菜含油量相关性状表现为多基因控制的数量性状,基因表达受环境影响较大,本研究为甘蓝型油菜含油量钝感基因的筛选提供了依据,有助于促进甘蓝型油菜高油稳油分子标记辅助育种的发展。     

玉米主要营养品质性状的QTL定位

淀粉、蛋白质和油分是普通玉米籽粒的主要营养成分.本研究通过SSR分子标记,以玉米(Zeamays L.)杂交种黄C×178的F2群体构建的遗传连锁图,结合2007年重庆(F口2)、2007年海南(F2.3)和2008年重庆(F2:4)三个环境品质检测结果,运用区间作图法,对品质性状进行全基因组QTL扫描,共检测到16个品质性状QTL.其中,油分含量检测到6个位点,解释性状表型变异6.2％～17.8％;蛋白质含量检测到5个位点,解释性状表型变异6.3％～ 12.0％;淀粉含量检测到2个位点,解释性状表型变异6.3％～10.0％.16个QTL多数以超显性和部分显性为主.这16个与品质性状相关的QTL可作为利用分子标记辅助育种途径进行玉米遗传改良的依据.     

波兰小麦品系XN555×普通小麦品系中13衍生重组自交系(RILs)群体中籽粒品质相关性状QTL定位

小麦籽粒品质相关性状属于数量性状,由多基因控制。为了探索小麦(Triticum aestivum L.)品质相关性状的遗传基础,以波兰小麦(Triticum polonicum L.)品系XN555×普通小麦品系中13产生的重组自交系(recombinant inbred lines,RILs)群体(包含99个F10株系)为研究材料,采用SSR(simple sequence repeat)分子标记技术构建遗传连锁图谱;根据2012年和2013年的表型数据,采用完备区间作图法(inclusive composite interval mapping,ICIM)定位籽粒硬度、籽粒蛋白质含量、面粉蛋白质含量和湿面筋含量等品质性状QTL。获得了由241个SSR标记位点组成的A、B染色体组的14个连锁群图谱,覆盖基因组1 338.92 cM,标记间的平均遗传距离为5.56 cM。共定位24个品质性状QTL,分布在1A、3A、4A、5A、6A、1B、2B、3B和5B等9条染色体上。其中,籽粒蛋白质含量和面粉蛋白质含量各7个QTL,湿面筋含量和籽粒硬度各5个QTL,4个性状的单个QTL可分别解释表型变异的8.30%～29.69%、6.90%～29.50%、10.10%～18.43%和7.93%～30.49%。两年都在6A染色体的Xbarc104～Xcfa2114标记区间内与Xbarc104相距1.2 cM处检测到湿面筋含量QTL,并于2012年和2013年分别检测出了面粉蛋白质含量和籽粒蛋白质含量的QTL。本研究为利用波兰小麦改良普通小麦以及在小麦品质改良中应用分子标记辅助选择提供依据。     

玉米自交系产量和品质相关性状与简单重复序列(SSR)的关联分析

为寻找并确定控制玉米产量、品质的基因组区域,本研究利用64对核心SSR(simple sequence repeats)标记对257份玉米(Zea maysL.)自交系构成的群体进行基因分型,分析群体连锁不平衡位点、群体结构,在此基础上,采用TASSEL软件的GLM(general linear mode)程序对株高、穗位、生育期、穗长、穗行数、百粒重、脂肪含量、蛋白质含量和淀粉含量共9个性状的表型数据与标记进行回归分析,确定标记对表型的解释率。结果表明:(1)在公共图谱上的SSR位点组合都有一定程度连锁不平衡(linkage disequilibrium,LD),P<0.01时,LD成对位点占总位点组合20.29%,D’>0.5成对位点比例为12.65%。(2)SSR数据遗传结构分析表明,群体可分为5个亚群。(3)共鉴定出26个标记位点与9个性状相关联,大多集中在4、6、7和10染色体上,其中第7染色体上标记最多,为5个。8个位点的变异分别与株高、穗位、生育期、穗长、穗行数和蛋白质含量等6个表型性状极显著相关(P<0.01),分别为umc1294作用于株高,对表型的解释率为7.2%;umc1741及phi116作用于穗位,对表型的解释率为11.37%和8.57%;phi328175及phi260485作用于生育期,对表型的解释率为4.74%和5.6%;umc1741作用于穗长,对表型的解释率为5.77%;umc1309作用于穗行数,对表型的解释率为6.68%;bnlg1450及bnlg1185作用于蛋白质含量,对表型的解释率为9.41%和9.81%;其他18个标记与9个性状显著相关(P<0.05)。与单个性状关联的标记数目为1～7个,解释率为4.74%～14.31%。与产量相关性状关联的位点(次)累计为30个,与品质相关性状关联的位点(次)累计为7个,位点数目上品质性状远少于产量性状。部分标记与多个性状关联,可能是性状相关或一因多效的遗传基础,一些标记同时与某性状关联,多数标记与定位于遗传图谱的QTL(quantitative trait loci)一致,也有互补性。研究结果表明,这些位点及其区域内存在很多与产量、品质等性状相关的QTL,对提高玉米产量、改善玉米品质可能起到重要作用。     

玉米强优势组合7个主要穗部性状在3种环境下的QTL分析

玉米产量是遗传基础复杂的数量性状。利用玉米(Zea mays L.)单交种烟单 14 号杂交组合的 F1(Mo17×黄早四)自交后形成的 191 个 F2单株作为构图群体,构建了由扩增片段长度多态性(AFLP)和简单重复序列(SSR)两种标记组成的遗传图谱。F2继续自交衍生的 184 个相应 F2∶3家系用于玉米 7 个穗部性状表型的田间鉴定。采用以混合线性模型为理论基础的复合区间作图法和配套软件 QTLmapper/V2.0,在 3个环境下共检测到 76 个穗部性状的数量性状基因座(QTL)。其中穗粒重、穗重、出籽率、穗长、秃尖长、穗粗和轴粗的 QTL 数目分别为 8、8、11、10、9、10 和 20 个。大多 QTL 仅在单一环境下被检测到,单个 QTL解释的表型变异率很低,仅有 5 个 QTL 的加性效应贡献率大于 10%,绝大多数 QTL 显性效应贡献率小于 1%。基因作用方式 29%的 QTL 为加性,47%为部分显性,11%为显性,13%为超显性。控制玉米穗部性状的 QTL 在染色体间分布不均匀,且呈现成簇分布、毗邻分布等特征。各个 QTL 位点上起增效和减效作用的等位基因在双亲间分布不均匀,两个亲本均可以提供增效或减效等位基因。本研究结果对于玉米高产分子育种中分子标记辅助选择(MAS)和亲本选配等问题具有启发和指导作用。     

水旱稻根基粗、千粒重主效QTL近等基因系的构建及鉴评

近等基因系的选育是分子遗传图谱构建、数量性状基因定位及分子标记辅助育种的重要基础之一。本文利用分子标记辅助目标性状QTL前景选择及恢复轮回亲本基因组的背景选择，再结合表型选择获得了定位在水稻4号、6号染色体上根基粗、千粒重2个主效QTL的近等基因系。其中有9个系入选旱田根基粗主效QTL brt4.1的近等基因系，根基粗的表型值为1.07～1.16mm，较轮回亲本越富提高6.11％～15.18％，平均遗传背景恢复率达97.22％；千粒重主效QTL的近等基因系有11个系入选，千粒重的表型值为21.25～26.25g，较轮回亲本越富的增幅为7.05％～32.16％，平均遗传背景恢复率为95.97％。另外，本文还就分子标记辅助近等基因系选育中背景选择标记数的确定、基于QTL-NILs的基因克隆等进行了讨论。     

玉米叶夹角和叶向值的QTL定位

叶夹角和叶向值是评价玉米株型的重要指标。本研究以甜玉米自交系组合T14×T4的F2为作图群体,构建了包含192个SSR标记位点的遗传连锁图谱,覆盖玉米基因组1260cM,平均图距6.56cM。通过测定F2、F2:3家系的叶夹角和叶向值,应用复合区间作图法在两个世代中共检测到26个QTL,其中14个与叶夹角相关的QTL,分别位于第2、5、6、7和8染色体上,单个QTL可解释的表型变异为3.3%～26.2%;12个与叶向值相关的QTL,分布于第1、2、3、7和10染色体上,单个QTL可解释的表型变异为3.1%～20.7%。在第2、3、5染色体上分别检测到1、1、2个同时在F2、F2:3家系都稳定表达的QTL,分别落在区间bnlg1329～bnlg1613、umc1148～umc2275和umc1097～umc1692,可作为相关数量性状基因的候选基因。发现1个同时控制叶夹角和叶向值性状的QTL,位于第2染色体上的bnlg1017-umc2129区间,对两性状的表型贡献率分别为10.8%和10.6%。本研究的结果有望为玉米耐密型育种及分子辅助选择育种提供一定的理论依据。     

水稻千粒重和垩白粒率相关性分析及其QTL定位

千粒重和垩白粒率是水稻重要的产量和品质性状。本研究以粳稻Sasanishiki为受体、籼稻品种Habataki为供体构建的染色体片段渗入系群体(Introgression Lines,ILs)为材料,在两个不同的环境下进行了千粒重和垩白粒率相关性分析和QTL定位。相关分析表明,在两个不同的环境下,群体千粒重和垩白粒率之间相关性不显著。两个环境共检测到9个稻谷千粒重QTL、5个糙米千粒重QTL和6个垩白粒率QTL,分布在水稻的10条染色体上。在两个不同的环境下重复检测到其中的5个QTL,即影响稻谷千粒重的qPTGW3、qPTGW8.2和qPTGW11.1及控制垩白粒率qPGWC1.1和qPGWC1.2。其所对应染色体片段渗入系的相应性状与背景亲本Sasanishiki的表现型差异在连续两个环境中均达到显著(P0.05)或极显著(P0.01)水平。这些材料为优良粒重和垩白粒率QTL的克隆及水稻产量和外观品质的标记辅助选择(MAS)育种利用提供了基础。     

不同生态因子条件下西藏青稞种子表型性状的相关分析

为了研究西藏青稞种质籽粒遗传变异程度、变异规律、地理因子对籽粒表型性状的影响程度,确定决定籽粒表型的关键性状,从而为青稞育种提供籽粒表型基础模型,本研究以527份西藏青稞农家种、野生近缘种为试验材料,基于青稞籽粒表型性状变化和相关地理环境因子,采用数字图像分析法对西藏青稞农家种、野生近缘种等527份青稞种质资源籽粒长、粒宽、粒长宽比、粒面积、圆度值、密度指数和千粒重(TKW)7个表型性状进行精确测量,并进行典型相关分析、聚类分析和主成分分析。结果表明,西藏青稞种子表型存在广泛的变异类型,TKW的变异系数最大,粒长的变异系数最小。典型相关分析显示,海拔、经度和纬度地理因子与7个籽粒表型性状间存在着显著相关关系(α=0.05),海拔高度的增加可使青稞粒面积、粒长宽比、粒圆度值增加,而粒长逐渐减少。纬度和经度的增加与粒长呈正相关,并与TKW有一定联系。籽粒7个表型性状的聚类分析表明,527份青稞材料可聚为3大类群,各类群表现一定的地理分区。主成分分析显示,青稞籽粒TKW、面积、粒宽、粒密度可代表7个籽粒表型性状的变异,且表现出以粒宽、TKW、粒面积为主反映种子大小的指标及以长宽比、粒长、圆度值为主反映种子形状的指标。西藏青稞种质资源籽粒表型变异极为丰富,并与多变的地理因子显著相关。青稞籽粒表型性状可分为种子大小和种子形状2个方面,两者对千粒重贡献率分别达到60.3%和33.8%,且表现为独立遗传特性,这说明在今后的青稞育种工作中,应以籽粒大小指标为重,兼顾籽粒形状,该研究结果为西藏青稞高产栽培育种提供了一定的理论依据。     

玉米苗期磷效率相关根系分泌物的QTL定位

为了充分利用现有的遗传信息和基因资源,揭示玉米磷营养高效的分子机制,本研究以磷高效玉米自交系082和磷低效玉米自交系掖107为亲本组配的F2世代为作图群体,采用SSR和AFLP分子标记构建了遗传连锁图,以两个时期,两个磷水平和两个地点共4种环境下的241个F2∶3家系各性状的平均值作为表型值,采用复合区间作图法定位了磷效率相关的3种根系分泌物的QTL。四种环境下检测表明,(1)检测到4个影响酸性磷酸酶活性的QTL,其中有两个QTL AP1-KXNP和AP9-KXNP被重复检测到,分别分布在第1和9二条染色体上,所在标记区间分别为bnlg1268a-umc1290a和P1M3/d-P1M3/g,在染色体上的位点分别为bin1.09和bin9.04,单个QTL解释酸性磷酸酶变异的9%～16%,2个QTL共解释酸性磷酸酶变异的25%;(2)检测到5个影响有机酸含量的QTL,其中只有1个在两种环境下被重复检测到,位于第9染色体上,标记区间为P1M3/f-P1M7/g,在染色体上的位点为bin9.03;(3)检测到5个影响H+含量的QTL,但没有一个被重复检测到。结果表明,影响酸性磷酸酶活性的两个QTL AP1-KXN...     

Genetic variability and association studies in pod and seed traits of <Emphasis Type="Italic">Pongamia pinnata</Emphasis> (L.) Pierre in Haryana,India

Forty Candidate Plus Trees (CPTs) of Pongamia pinnata were selected based on the morphometric traits to identify suitable seed sources with high oil content and for production of quality seedlings for mass afforestation in different forestry and agroforestry programmes. Significant genetic variability and association were recorded among 40 CPTs for pod and seed traits. Maximum 100-seed weight (186.80 g) and pod-weight (403.94 g) was recorded in CPT-33, while CPT-18 showed maximum oil content (44.07%). In general, phenotypic coefficient of variation was higher than genotypic coefficient of variation indicating the predominant role of environment. High heritability (broad sense) and genetic gain observed for pod–seed ratio (99.00%, 87.78%), 100-seed weight (100.00%, 66.99%) and 100-pod weight (98.00%, 57.38%), respectively indicate additive gene action. Seed weight and pod weight showed positive and significant correlation with oil content. CPTs 18, 20, 33, 13 and 29 were found to be the best on the basis of oil content and pod–seed characters.     

DETECTION AND VERIFICATION OF QUANTITATIVE TRAIT LOCI AFFECTING TOLERANCE TO LOW PHOSPHORUS IN RICE

Phosphorus (P)-deficiency in rice (Oryza sativa L.) may cause yields reductions. This research was conducted to map quantitative trait loci (QTL) for tolerance to low-P stress in a double-haploid (DH) line, and to verify these loci in another SSD9 population, which is the ninth generation of single-seed-distribution population derived from the same parents. Two populations were cultured solution at different period. By using the linkage map, QTLs for traits associated with tolerance to low-P stress were located. Results indicated that for DH population, one restricted fragment length polymorphism (RFLP) marker located on chromosome 6 was closely associated with relative root dry weight, relative shoot dry weight, and relative total dry weight. Two QTLs affected relative P uptake content. One micro-effect QTL was found to be associated with relative P utilization efficiency. For relative amounts of root exuded acid phosphatase, relative P allocation between shoot and root, relative plant P concentration, and relative shoot P concentration, one micro-effect QTL was detected for each one. Quantitative trait loci for 3 traits were detected for both DH and SSD9 populations, but the loci for each located trait were inconsistent between two populations; the reason for inconsistency in QTLs was analyzed. The main reason could be the difference in solution environment.     

Establishment of sesame germplasm core collection in China

A sesame core collection containing 453 accessions was established by assessing genetic diversity of 4251 accessions collected in China. The accessions in the whole collection were grouped based on their origin, varietal and agro-ecological type. A computer program was used to cluster the data of 14 traits from the random small sample. Ward's method was chosen as the desirable method for clustering sesame germplasm resources. A set of technical methods for establishing core collection has been developed through determining the number of selected accessions based on the diversity distribution. The agronomic traits of the pre-selected core collection were investigated and tested in three ecological locations in China for two years. Among six qualitative traits, including plant type and flower color in a total of 5304 accessions, 97.85% was completely the same as the original data, and three quantitative traits, including growth period and plant height, were significantly and positively related with the original data. The representativeness assessment of the final core collection indicated that 35 phenotypes of 10 qualitative traits in the core collection were basically similar to those of the pre-selected core collection. Six feature values such as mean, standard deviation etc. of four quantitative traits including oil content and 1000-seed weight were close to those of the pre-selected core collection. The final core collection possessed a fair representativeness of the pre-selected core collection.     

Patterns of diversity in pigeonpea (<Emphasis Type="Italic">Cajanus cajan</Emphasis> (L.) Millsp.) germplasm collected from different elevations in Kenya

Pigeonpea germplasm accessions collected from low (<500 m), medium (501–1000 m), high (1001–1500 m) and very high elevation zones (>1500 m) of Kenya were evaluated for 15 agronomic traits and seed protein content at ICRISAT, Patancheru, India. There were significant differences (P < 0.001) among elevation zones for the number of primary and secondary branches, days to 75% maturity, pod length, seeds per pod, 100-seed weight and seed yield. Mean values indicated that the accessions from low elevation zone were significantly different from those collected in higher elevation zones for early flowering and maturity, number of primary branches, pod length, number of pods per plant, seeds per pod, 100-seed weight, seed yield and harvest index. None of the accessions collected in Kenya belonged to extra early (<80 days to 50% flowering) and early (80–100 days to 50% flowering) maturity groups, as defined by time to flowering at Patancheru, India. Mean diversity index based on all characters indicated that accessions from the low elevation zone are more diverse than those from the higher elevation zones. Frequency distribution for trait extremes indicated that the accessions from the low elevation zone were early to flower and mature, short statured, produced more primary and secondary branches with high pod bearing length, long pods, more pods per plant, more seeds per pod, a high seed yield and harvest index. Accessions from the very high elevation zone were late flowering, with a large number of tertiary branches, large seeds and a high shelling percentage and could be a source for cold tolerance and the breeding of vegetable types. Results suggest that the elevation of collection sites is therefore a very important determinant of variation patterns of pigeonpea in Kenya.     

Two years of a field study on sesame growth and yield,nutrient uptake by PGP bacteria application and capsule type

Abstract

A two-year field experiment was conducted to study PGP bacteria on growth and yield productivity of sesame. Factors were control, Nitroxin, Biophosphor, and an equal combination of biofertilizers along with sesame capsule type. 1000-seed weight and oil content increased in the second year, but, seed yield reduced (-12.6?g m²), which represented a negative relationship between seed weight and yield. The effect of year on No. of single and multi-cap node plant^?1 was reversed. Seed yield, chlorophyll, protein, and N increased in the multi-cap seed, whereas, 1000-seed weight and seed weight plant^?1 was decreased. Maximum yield and yield components were achieved in the second and first year, respectively, along with the multi-cap seed. Nitroxin, after the equal combination, was approximately showed the maximum enhancement of growth and yield productivity of sesame. The most seed yield (4261 k ha^?1) was performed in the first year, combined biofertilizers and multi-cap seed, whereas, the highest oil content was gained in the second year and single-cap that it was due to the higher N and P use efficiency in the first year. No. of node plant^?1 and capsule No. plant^?1 showed the most correlation with the other parameters. Seed yield was correlated with No. of node plant^?1 (r?=?0.925) and leaf dry weight (r?=?0.885). The N and P use efficiency had been higher in the first year, multi-cap, and equal combination. Nitrogen Use efficiency was higher compared to phosphorous. The uptake of N and P by sesame increased with the integrated application of different bacteria.     

油茶籽脱壳机的研制与应用

采用挤压和碾磨原理以及风筛复合分离原理设计开发出了油茶籽脱壳机。油茶籽含水率和辊筒线速度是影响脱壳分离效果的主要因素。适宜的脱壳工艺条件为油茶籽含水率5%～20%，辊筒线速度8.90～10.00 m/s，在此工艺条件下，油茶籽脱壳率≥98.5%，仁中含壳≤4%、壳中含仁≤1%。油茶籽脱壳机成功投入了生产实践应用，获得了质量优良的油茶籽油和脱壳油茶籽饼粕，提高了油茶籽加工的经济效益。     

Identification of simple sequence repeat (SSR) markers for acid detergent fiber in rice straw by bulked segregant analysis

Rice straw is a significant energy source for ruminant animals. The acid detergent fiber (ADF) content of rice straw is negatively related to intake potential of forages. Therefore, improving the digestibility of rice straw by reducing ADF content is a necessary goal in breeding programs. In the present study, simple sequence repeat (SSR) markers and the bulked segregant analysis (BSA) approach were used to identify molecular markers associated with ADF. A total of 121 BC1F1 plants derived from the cross of JX974 (a cultivar with high ADF, 36.6%) and Dongxiang wild rice (a wild rice with low ADF, 31.3%), with JX974 as a recurrent parent, were used to conduct BSA. Phenotypic analysis showed that ADF displayed a normal distribution in BC1F1 population, indicating the involvement of polygenes. A SSR marker, RM566 on chromosome 9, was identified for ADF. A small linkage map consisting of five markers was constructed by adding four other markers, and a quantitative trait locus (QTL) controlling ADF was mapped at the RM321-RM566 interval, with a distance of 3.9 cM to RM566. This QTL explained 12% of the total phenotypic variation of ADF, and its additive effect was 3%. This study is the first step to map QTL for ADF, one of the plant cell wall components in rice.     

氮、磷、钾、硼肥对甘蓝型油菜籽品质的影响

以多个正在大面积应用的甘蓝型油菜品种为研究对象,在长江流域冬油菜主产区的10个省（市）布置氮、磷、钾和硼肥田间肥效试验共284组,通过多点试验分别探讨当前生产条件下施用氮、磷、钾、硼肥对双低和双高甘蓝型油菜籽含油量、蛋白质、芥酸、硫甙的影响。结果表明,双低油菜籽平均含油量为41.66%,双高油菜含油量明显低于双低油菜,仅为38.92%。氮、磷、钾和硼肥施用对油菜籽的品质效应在不同试验点表现不尽相同,其总体趋势是:在磷、钾、硼肥基础上施用氮肥提高籽粒蛋白质含量而降低油分含量,且随氮肥用量的增加效果更明显,施氮对双高油菜油分及蛋白质含量的影响程度大于双低油菜;施磷、钾或硼肥有提高油菜籽含油量而降低蛋白质含量的趋势;施肥对油菜籽硫甙和芥酸含量有一定影响,但对品质影响不大。油菜籽含油量与收获指数、千粒重显著正相关,与蛋白质含量呈负相关。研究结果显示,在施氮的基础上配合施用磷、钾和硼肥能减少因施氮引起的油分损失。