CIMMYT玉米群体Pob101的改良与利用研究

外来种质的引进与利用是解决我国玉米育种种质资源狭窄的重要途径。通过平均数、配合力和杂种优势分析,研究CIMMYT极早熟群体Pob101生态适应性的改良效果及其与我国主要种质的杂种优势关系。分析表明,群体产量平均每轮增益5.69%,生育期平均每轮下降3.8d,散粉期平均每轮下降1.3d,抽丝期平均每轮下降1.8d,穗位高和株高每轮下降10.33cm和5.37cm。与5个测验种的测交组合产量平均每轮增益4.02%,配合力和杂种优势都有所提高。Pob101群体与掖478有较近的亲缘关系,可以将掖478导入群体Pob101以改良其产量性状。     

两个热带玉米复合群体相互轮回选择遗传改良效益研究

利用半同胞相互轮回选择法对桂综3号和桂苏综两个热带复合群体进行两轮改良后, 选用黄早四、掖478、丹340、Mo17等4个测验种作母本,各轮改良群体作父本,按NCⅡ遗传交配设计组配测交种,对各轮群体、群体间杂交组合和测交种进行选择效果评价。结果表明,桂综3号、桂苏综及其杂交组合产量平均每轮增效分别为53、645、390 kg/hm²;群体组合超亲优势由5.7%提高到13.5%。C₂群体与C₀相比,桂综3号的产量一般配合力效应从-5.32增加到-1.55,桂苏综的一般配合力效应从0.10增加到6.55。桂综3号、桂苏综与掖478、丹340的特殊配合力都得到一定的提高。其他农艺性状随各轮对产量相互轮选择发生不同程度的变化,其中出籽率和千粒重是随轮次改良向增加方向发展,秃尖长也随着减少,其他性状变化不大。     

S_1家系密植鉴定选择对群体配合力的改良效果

利用S1家系密植鉴定改良方法对中综6群、瑞德群、黄改群、先玉335群进行1~2轮改良,获得9份群体。以9份群体为父本,自交系丹598、郑58、吉853为测验种,配制27份杂交组合,进行产量配合力比较试验,从单株产量、穗部性状和配合力角度分析群体改良的效果。结果表明,改良群体单株平均产量均有增加,穗部性状向有利于高产的方向发展。中综6群经过两轮改良后,一般配合力效应从C0的-4.44增加到C2的3.84;瑞德群经过一轮改良后一般配合力效应从C0的-1.44增加到C1的2.9;黄改群从C0的-2.83增加到C1的1.93,一般配合力效应均达到极显著水平。特殊配合力排前两位的杂交组合为郑58×黄改群、丹598×瑞德群。     

Suwan与我国四大玉米种质的配合力和杂种优势分析

采用NCII设计,研究了4个Suwan群体与我国四大骨干自交系的配合力和杂种优势。结果显示:Suwan群体选系有较好的一般配合力,与四大骨干自交系有较高的特殊配合力和较强的杂种优势。其中,Suwan3的选系一般配合力较高,与丹340组配易形成较强的杂种优势。     

两种改良方法对玉米辽旅群体改良效果和杂优模式分析

旅大红骨是我国重要地方种质资源，通过S₁家系密植鉴定改良法和半姊妹家系配合力改良法对辽旅群体进行两轮改良。结果表明，两种方法显著改善群体的穗行数和出籽率，提高了群体穗粗、穗行数和出籽率的一般配合力及穗粗、百粒重的杂种优势。经过两轮S₁家系密植鉴定法改良，原始群体的产量一般配合力提高了8.96，超亲优势提高了12.22%；半姊妹家系配合力改良法产量一般配合力提高了4.75，超亲优势提高了11.49%。S₁家系密植鉴定法改良后的群体性状优良，一般配合力更高，杂种优势更强，与玉米各类群间特殊配合力没有明显差异，更适合对辽旅群体进行后续改良。     

玉米Tuxpeno-Reid和Suwan-Lancaster合成群体相互轮回选择效果及杂种优势研究

采用属Reid自交系和属Tuxpeno自交系形成墨瑞C0以及用属Suwan自交系、Mo17和78599形成苏兰C0。两个群体在4次遗传平衡后按半同胞相互轮回选择后分别形成改良一轮的墨瑞C1和苏兰C1。经多点产量比较,墨瑞C1×苏兰C1比墨瑞C0×苏兰C0的产量提高7.84%,达到极显著水平,而两个群体本身的产量变化不显著。群体间的平均杂种优势也从改良前的9.86%提高到改良后的16.29%。根据SSR标记计算,相互轮回选择对群体间的遗传距离略有提高。     

玉米品系内改良S1选择方法与技术

根据玉米群体轮回选择的基本原理和方法,建立起一套简单易行的群体改良S₁选择方法,其主体技术包括组建一个好的基础群体,利用控制授粉提高优良基因的频率,借助互交使基因重组.采用此方法对CIMMYT提供的热带玉米群体进行了3轮选择,群体产量平均每轮增益为6.4%,群体测交种产量平均每轮增益为6.3%.表明群体产量的一般配合力有较大的提高。     

热带玉米Suwan1群体导入不同类型温带种质的遗传分析

采用不完全双列杂交法,分别将热带玉米Suwan1群体与我国温带玉米5大类群骨干自交系杂交,形成新的综合种,再与4个测验种杂交,组配36个杂交组合。通过2年1点的田间杂交组合8个表型(产量相关性状)评价,进行方差分析和配合力效应分析。方差分析表明,各杂交组合之间8个性状差异均达显著或极显著水平。产量一般配合力效应值大小为CML171/Suwan1Dan340/Suwan1P159/Suwan118599/Suwan1Chang7-2/Suwan1Mu6/Suwan1zheng58/Suwan191-95/Suwan1Mo17/Suwan1。根据联合产量分析,在36个组合中18599×Dan340/Suwan1和Dan340×CML171/Suwan1的杂种优势表现较强。由此,表现较好的杂种优势组型为PB、Tangsipingtou×Lvdahonggu/Suwan1(Reid/Suwan1)、Reid×Tangsipingtou/Suwan1、Reid×Lancaster/Suwan1,将Suwan1导入我国5大类群所形成的新种质对玉米的产量和其他性状的改良可以取得显著成效。     

热带玉米Suwan群体的遗传特性及育种潜势

基于对玉米Suwan 1、Suwan 3和Suwan 5群体的植物形态学农艺性状特征特性调查与玉米Suwan 1群体的遗传潜势研究,对玉米Suwan 1、Suwan 3和Suwan 5群体的遗传特征特性和Suwan 1群体进行方差分析。结果表明,热带玉米Suwan 1群体的综合性状包括育种产量潜力、基因加性效应积累等方面优于Suwan 3和Suwan 5群体;基于导入玉米Suwan 1群体后的杂种优势模式及产量表现,根据贵阳市两年田间产量鉴定结果发现,将Luda Red cob/Suwan 1类群合并的新种质与PB类群的平均产量最高。根据Suwan 1种质导入我国5大玉米类群后顶交种的配合力和杂种优势组型,经过2年多点的田间试验鉴定得出强杂种优势组型PB×Luda Red cob/Suwan 1、CIMMYT×Reid/Suwan 1、CIMMYT×Luda Red cob/Suwan 1和PB×Reid/Suwan 1。同一地点不同年际间田间试验鉴定,试验点次较少,有必要对优良热带玉米Suwan 1群体的遗传潜势及种质改良利用等进行深入的、更全面的研究。     

肯尼亚玉米群体改良方法的评价

群体内改良采用混合选择法(M)、穗行选择法(E)、半同胞选择法(H)、S_1选择法(S)和全同(?)轮回选择法(F)。其中穗行选择法的产量增益率最为稳定一致(接近3%/轮)。群体间改良采用交互轮回选择法(R)、S_1选择法和穗行选择法。交互轮回选择法的每轮增益近7%,而穗行选择法在品种杂交组合中的增益很少。从交互轮回选择的 C_2、C_3和 C_4轮群体中选育自交系(分别选至 S_3代),然后进行所有可能的杂交组配。品比试验结果,在抗倒伏方面选择增益显著,最佳三交种的增益高于群体杂交种2～5%     

马铃薯新品种‘冀张薯13号’的选育

冀张薯13号’是张家口市农业科学院以‘3号’为母本,‘丰收白’为父本,通过有性杂交经系统选育而成,2013年通过河北省农作物品种审定委员会审定,审定编号：冀审薯2013001号。该品种为中晚熟加工型品种,2010～2011年参加河北省区域试验,平均产量1678 kg/667 m2,比对照‘夏坡蒂’平均增产29.24%。该品种适于河北省张家口和承德等地区种植。     

Correlation studies on 1000-true-seed weight,tuber yield and other morphological traits in potato (Solanum tuberosum L.)

Summary Simple phenotypic, genotypic and environmental correlation coefficients were calculated from one year's data for nine characters in F₁ seedlings of 72 crosses and 18 parents of potato (Solanum tuberosum L.). Crosses were made in a line x tester model having 12 female lines and six male testers. The experiment was designed as a randomized block replicated three times at Kufri, Simla (India) during the 1979–80 crop season. Positive phenotypic and genotypic correlations of 1000-TPS weight were found with total tuber yield, number of leaves on the main shoot, number of shoots per plant and harvest index. The results suggest that 1000-TPS weight could be used when attempting to select for yield and other characters in F₁ seedlings. Adapted from a thesis submitted and approved for the degree of Doctor of Philosophy of Agra University.     

水稻区域试验点对品种判别能力估计方法的研究

 提出利用AMMI 模型中达显著水平的主成分轴上环境分量作为水稻区试点对品种判别能力的估算依据, 并设计了估算参数D j 。试验表明, D j 值小的试点, 其与基因型互作效应弱, 包含较少的互作信息。以浙江省早籼稻区域试验15 个区试点为例, 剔除D j 值最小的4 个试点后, 交互作用值仅损失10. 12%。     

Breeding for drought tolerance: Direct selection for yield, response to selection and use of drought-tolerant donors in upland and lowland-adapted populations

Drought is the most important constraint reducing rice yield in rainfed areas. Earlier efforts to improve rice yield under drought mainly focused on improving secondary traits because the broad-sense heritability (H) of grain yield under drought stress was assumed to be low, however gains in yield by selecting for secondary traits have not been clearly demonstrated in rice. In present study, the effectiveness of direct selection for grain yield was assessed under lowland reproductive stage stress at Raipur in eastern India and under upland reproductive stage drought stress at IRRI. The selection under severe stress (in both upland and lowland trials) resulted in greater gains under similar stress levels (yield reduction of 65% or greater under stress) in evaluation experiments than did selection under non-stress conditions, with no yield reduction under non-stress conditions. We observed similar H of grain yield under stress and non-stress conditions, indicating direct selection for yield under drought will be effective under both lowland and upland drought stresses. None of the secondary traits (panicle exsertion, harvest index, leaf rolling, leaf drying) included in our study showed a higher estimate for H than grain yield under stress. Secondary traits as well as indirect selection for grain yield under non-stress situation were predicted to be less effective in improving yield under drought in both lowland and upland ecosystem than direct selection for grain yield under the respective stress situations. The low, but positive values observed for genetic correlation (r_G) between yield under stress and non-stress indicated that it is possible to combine drought tolerance with high-yield potential but low values also indicated that selection for grain yield needs to be carried under stress environments. The study also indicated that under lowland drought stress, the use of highly drought-tolerant donors, as parents in crosses to high yielding but susceptible varieties resulted in a much higher frequency of genotypes combining high-yield potential with tolerance than did crosses among elite lines with high-yield potential but poor tolerance. Breeding strategies that use drought-tolerant donors and that combine screening for yield under managed drought stress with screening for yield potential are likely to result in the development of improved cultivars for drought-prone rainfed rice producing areas.     

应用轮回选择法改良四倍体甜菜初探

本研究为应用轮回选择法改良已有的四倍体甜菜品系，获得了一轮轮回群体，表明了此方法的可行性；试验中应用了种株腋芽培养技术，各系号的基因型均得到了一定数量腋芽培养的母根。     

Determining Selection Gains and Discriminating Environments via GGE Biplots

Abstract

Genetic variation is the basis for meaningful selection; thus, the use of locations that discriminate or result in greater variation among genotypes, for a trait or trait package should promote accurate selection of superior genotypes. The objectives of this study were to quantify the gains by selection in discriminating locations using superior parents for single or multiple-trait populations. GGEbiplot software was used to identify two levels (high and low) of discriminating locations for each of three distinct populations of cotton (Gossypium hirsutum L.). Populations were obtained by crossing parents recommended by a least squares means analysis for each population criteria, which included parents/populations selected for: (a) lint yield; (b) fiber micronaire, length, strength, uniformity, and elongation; and (c) lint yield, lint percent, fiber micronaire, length, and strength. F₂ plants in 2003 and F_2:3 plants in 2004 were planted in the high and low discriminating locations for each selection criteria. Heritability estimates (h²) were calculated by regressing the F_2:3 plants on their F₂ parents. Genotypic variance was greater among F_2:3 progeny in discriminating environments compared with non-discriminating environments, regardless of population criteria. Heritability was greater in the population containing fiber traits compared with yield. The results of this study suggest that using discriminating locations during the selection phase of a breeding program can increase genotypic variance and enhance selection accuracy.     

Agronomic performance of rice breeding lines selected based on plant traits or grain yield

Selection for yield per se has greatly contributed to yield improvement in many crops. It is expected that selection based on plant traits is more effective in increasing crop yield potential. This study was conducted to compare the effectiveness of trait-based and yield-based selection in increasing rice yield and to determine whether lines with ideotype traits have the potential to express higher yield under optimal crop management conditions. Lines were selected based on plant traits or on grain yield measured in a breeder's replicated yield trial. The main target traits for selection were plant height, leaf and panicle morphology, grain size, total dry weight, and grain-filling percentage. Yield performance of trait-based selection was compared with that of yield-based selection in an agronomic trial with optimum crop management for three seasons. Trait-based selection increased leaf area index and total dry weight but reduced spikelet number per m² and harvest index compared with yield-based selection. Consequently, selection based on plant traits did not increase grain yield compared with selection based on yield per se. In one of the three seasons, yield of trait-based selection was significantly lower than that of yield-based selection. Among all tested breeding lines, maximum yield was produced by yield-based selection and minimum yield came from trait-based selection. These results suggest that lines with ideotype traits did not express higher grain yield than lines selected based on yield per se under optimal crop management conditions, and yield-based selection was as effective in increasing rice grain yield as trait-based selection in the late generations of the breeding cycle.     

抗赤霉病小麦优异新种质的分子标记辅助选择

赤霉病(Fusarium head blight,FHB)是危害全球小麦生产安全的重要病害。创制抗赤霉病优异新种质是培育抗病新品种的首要任务。本研究以979-5(中感赤霉病)和苏麦3号(高抗赤霉病)杂交后代为材料,采用系谱育种法,综合利用农艺性状选择、SSR标记选择和赤霉病菌单花接种鉴定等技术,进行抗赤霉病新种质选育。结果表明:(1)用13个分别与苏麦3号3BS上主效抗赤霉病基因 Fhb1、6B上微效基因 Fhb2和5AS上微效基因 Fhb5紧密连锁的SSR标记对双亲进行分析,发现其中的6个标记在979-5和苏麦3号间扩增呈单态,另7个标记在双亲间扩增呈多态,表明979-5与苏麦3号在这3个基因位点具有较高的遗传相似性;(2)创制出中抗新品系13个,高抗赤霉病新品系7个,这20个新品系均携带有苏麦3号的 Fhb1基因位点,其中7个高抗新品系还兼具 Fhb2或 Fhb5标记位点的优异等位变异;(3)20个新品系不仅越冬抗寒性好,且株高较矮,生育期与亲本979-5相近,产量性状好,蛋白质含量、出粉率、湿面筋含量、面团稳定时间等籽粒品质性状较优,其中,k15、k32和k40三个新品系的四项品质指标均达到国家中强筋品种标准。育成的新品系可用作黄淮冬麦区抗赤霉病品种改良的优异育种材料。     

SDS沉淀值在小麦亲本选配及后代选择上的应用

为了给优质小麦新品种选育提供理论依据，利用4个“中筋（SDS沉淀值中等）／强筋（高SDS沉淀值）”或“中筋（SDS沉淀值中等）／中筋（SDS沉淀值中等）／／强筋（高SDS沉淀值）”杂交组合的5个F2衍生系统群在选择进程中杂种后代SDS沉淀值的分离表现．研究了杂种后代SDS沉淀值的遗传分离特点和选择方法，结果表明：（1）SDS沉淀值呈数量性状遗传，具有很高的遗传力。F1表型值从正负两个方向接近两亲中值，在分离中出现明显的超亲遗传。在99209、99190、99236、99201共4个杂交组合的杂种后代中，选育出SDS沉淀值比高值亲本辽眷10号（SDS沉淀值52．7）分别高出6．23、13．13、8．18和5．90mL的高代品系；（2）早代选择有效且重要，选择的关键世代是F3和F4代；（3）在杂种早期世代中，高SDS沉淀值的选株，后代容易分离出稳定的高SDS沉淀值品系，低SDS沉淀值的选株，后代一般不再分离出稳定的高SDS沉淀值品系；（4）在杂种后代选择进程中，高SDS沉淀值的遗传性稳定品系一般出现在F5～F7代。在杂种后代选择中，要重视早代选择，F2代可采用微量SDS沉淀值测定法．特别要注意F3、F4关键世代的选择。     

甜菜新品种甘糖三号的选育

甜菜新品种甘糖三号是以两个抗病高糖品系杂交而成的二倍体甜菜新品种，其亲本品系采用系统选育的方法。该品种块根产量高，工艺品质好，抗黄化毒病和白粉病，经区试结果，平均块根产量比对照增产１０．４％，含糖率（１８．１６％）提高０．４５％，产糖量比对照增加１３．１％。