大麦产量相关性状一般配合力的差异分析

为研究大麦产量相关性状一般配合力(GCA)的差异,筛选高GCA亲本,以我国不同产区具代表性的17份大麦新品种(系)为亲本材料,两年度采用NCⅡ设计对7个产量相关性状的配合力进行方差分析。结果表明,所有性状一般配合力(GCA)与特殊配合力(Special combining ability,SCA)方差在单年度或两年度达显著或极显著水平,且GCA方差普遍大于SCA方差,表明基因加性、非加性效应同时存在,并以加性效应为主。所有性状亲本间GCA差异显著,可针对目标性状筛选到高GCA亲本,如16号亲本(95033-1)在穗粒数、千粒质量及单株粒质量3个性状上GCA值均较高,是一优良亲本。亲本性状值与其GCA值间的相关性在不同性状上表现不同,如在株高、穗下节间长、穗长及穗粒数4个性状上,两者呈极显著正相关;在单株穗数与单株粒质量上,仅单年度检测到两者呈显著或极显著正相关;而对于千粒质量,两者相关不显著。因此,前4个性状可根据亲本性状值预测其GCA大小。综上,大麦杂交育种可针对目标性状选择高GCA亲本进行组配,提高后代选择效率。     

印水型杂交粳稻产量及产量构成因素的配合力分析

为确定新育成印水型杂交粳稻亲本的潜力,并为印水型杂交粳稻育种提供理论基础,本研究以4个不育系和4 个恢复系为亲本进行不完全双列杂交,研究产量及其构成因素的配合力。结果表明：产量性状一般配合力(GCA)方差均达到极显著水平,除结实率外,父本的一般配合力方差大于母本,单株产量、有效穗和结实率的特殊配合力(SCA)方差达到显著或极显著水平。139A和晚轮422 的GCA效应较高,产量性状以Ⅱ类为主,139A×晚轮422 和辽粳10A×晚轮422 的单株产量水平及组合SCA效应较高。父本GCA效应和组合SCA效应对产量性状的影响较大,母本GCA效应对产量性状的影响相对较小。本研究中,父本的遗传差异大于母本,对产量性状的影响也大于母本,139A和晚轮422 有较大的应用潜力。     

棉花复合杂交育成亲本主要产量性状的杂种优势及配合力分析

为测定利用复合杂交育成的5个亲本的育种应用潜力,将5个亲本与4个推广品种采用不完全双列杂交设计配制20个组合,对组合的产量及相关性状的杂种优势进行分析,并对5个亲本的产量及相关性状进行配合力分析.结果:铃数对产量的贡献最大;A1亲本在铃数,A2亲本在衣分,A3亲本在铃重,A 5亲本在铃重、衣分性状上一般配合力(GCA)为正,A 5亲本是一个较理想的亲本;具有较高特殊配合力效应(SCA)的组合有A5×B3、A2×B2、A3×B1.结论:利用复合杂交培育高配合力亲本是可行的;但不同来源的亲本在同一性状,同一亲本的不同性状间一般配合力(GCA)是不同的;同一性状的不同组合间,同一组合的不同性状间特殊配合力(SCA)效应也都存在大小或方向上的差异.     

2个玉米人工合成群体S2主要性状的配合力分析

以48-2,9636,RP125为测验种,采用不完全双列杂交设计,对2个玉米人工合成群体S260个单株的配合力进行研究,以分析不同群体自交后代间、群体内S2株系间、株系内个体间配合力差异。结果表明,除株高、穗位高、行粒数外,其余性状GP-5 S2GCA优于GP-4 S2,多数性状群体内S2株系间GCA具有较大差异,株系内个体间经济性状GCA的差异远远大于农艺性状;不同性状及同一性状不同群体自交后代所配组合SCA效应值达显著或极显著差异的数目均有一定差异,且GCA与SCA无明显相关关系。55,57,89,93,105,107株系多数性状具有较高的GCA,可能有较大利用潜势。     

新疆冬麦区AL型三系杂交小麦亲本配合力、杂种优势和聚类分析

为了解新疆AL型三系杂交小麦亲本间配合力及其杂种优势关系,利用稳定不育系8份,恢复力强的恢复系9份,按照NCⅡ不完全双列杂交(8×9)设计配制72个F₁杂交组合,对亲本及杂交组合的7个农艺性状进行配合力效应和杂种优势分析,再根据亲本性状和一般配合力划分杂种优势类群。结果表明,三系小麦杂交组合中普遍存在产量和产量性状杂种优势,针对强优势组合的亲本选择,双亲之一一般配合力(GCA)或双亲GCA之和为正值且相对较大;相关性分析表明,中亲优势与父本和母本GCA值之和呈极显著正相关,父本和母本的GCA相关性大于特殊配合力(SCA)相关性。针对6个性状的GCA效应值和性状表型值分别进行聚类分析表明,配合力距离远的亲本组配可能出现强优势杂交组合的几率较大,性状表型值距离较远的两个亲本同一性状之间的优势互补也可以在后代中表现出较强的杂种优势。将17个亲本划分为4个和5个类群,为后续AL型杂交小麦强优势杂交组合的配制提供了依据。     

小麦耐热性的双列杂交分析

通过测定基因型的膜热稳定性大小(RI％),对小麦的耐热性进行了6×6完全双列杂交分析。结果表明:亲本之间耐热性的一般配合力效应(GCA)、特殊配合力效应(SCA)和反交效应(R)均达到极显著水平,GCA、SCA和R三者均方之比为2.1:1:0.5;该性状的狭义遗传力估计大小为24.3％。     

普通玉米3个籽粒品质性状的配合力分析

以10个普通玉米自交系及其90个杂交组合在北京和山西2个地点的试验数据,分析了蛋白质、淀粉和油分含量的配合力效应。结果表明：(1) 各性状的一般配合力(GCA和特殊配合力(SCA) 均方极显著,且GCA均方大于SCA均方,说明它们在遗传上主要受加性基因效应的影响。(2) 杂交种的3个品质性状与亲本GCA平均值和SCA极显著正相关,但与亲本GCA均值间的相关性相对较强,其相关系数(r)分别为0.708**(蛋白质)、0.756**(淀粉)和0.772**(油分),表明提高亲本GCA对改良杂交种品质具有更大的作用。(3) 自交系BT1和E28的蛋白质含量GCA较高,掖478、昌7-2、掖107和48-2的淀粉含量GCA较高,E28、黄C和P138的油分含量GCA较高。     

冬小麦品种籽粒平均灌浆速率的遗传机制研究

研究采用Griffing方法Ⅰ,利用6×6完全双列杂交,对6个冬小麦品种的籽粒平均灌浆速率的遗传机制进行了初步探讨.结果表明平均灌浆速率的一般配合力(GCA)效应、特殊配合力(SCA)效应和反交(R)效应均不同程度的达到显著和极显著水平,其均方比1.4268∶1.6839∶1;平均灌浆速率遗传以非加性基因效应占优势,加性基因效应次之;其广义遗传力为60.67%,狭义遗传力为78.69%.以综合性状评价河农2552品种为好.     

杂交水稻品质性状的配合力及遗传力研究

为了给杂交水稻主要品质性状的选育提供依据,本研究以三系野败型杂交水稻的恢复系和微核心种质构成的112份优异品种为父本,以四个两系不育系和一个三系不育系为母本,按照不完全双列杂交设计配制了560个组合,分析各组合及其亲本的12个品质性状的配合力与遗传力。结果显示考查的12个品质性状的一般配合力(general combining ability,GCA)和特殊配合力(specific combining ability,SCA)均存在极显著差异,说明各性状受基因加性效应和非加性效应的共同作用,其中在直链淀粉含量、粒长宽比、粒长、粒宽、垩白粒率及垩白度等性状上基因的加性效应占主导地位;在蛋白质含量、糙米率、精米率、整精米率、透明度及碱消值级等性状上则以基因的非加性效应为主。同一组合在不同性状间及同一亲本所配的不同组合的SCA差异较大,最高或最低SCA的组合可来自不同GCA的亲本组合类型,表明亲本GCA与SCA没有固定联系。母本的GCA方差贡献率为0.76%~26.21%,父本的GCA方差贡献率为17.47%~81.94%,在各性状上母本GCA方差贡献率均比父本GCA方差贡献率小,说明各性状受母本(不育系)的影响均较小。直链淀粉含量、粒长宽比、粒长、粒宽、垩白粒率及垩白度的狭义遗传力较高,均在50%以上,可在低世代进行选择。     

玉米高赖氨酸和糯性基因聚合材料品质性状的配合力分析

为了解玉米高赖氨酸和糯性基因聚合材料品质性状的配合力效应,以优质基因聚合系及其亲本和常用玉米骨干自交系为材料,按9×15不完全双列杂交设计,进行品质性状的配合力研究。结果表明:5个品质性状的GCA和SCA均存在显著差异;各性状的GCA方差均大于SCA方差,GCA方差占基因型方差比例的大小顺序是含油量淀粉蛋白质谷氨酸赖氨酸;综合品质性状表现,三基因聚合材料QCL 8002-11(o2o16wx)和QCL 8006-2(o2o16wx)分别在增加赖氨酸含量和含油量方面有比较好的利用潜力,两基因聚合材料QCL 8009-5(o16wx)对增加谷氨酸和蛋白质含量、QCL 8003-2(o2o16)和QCL 8001-10(o2o16)对增加总淀粉含量有较好的利用潜力。     

三峡库区玉米地方品种配合力分析

为了明确三峡库区玉米地方品种育种潜势,以三峡库区常用的7个玉米自交系为测验种,采用NCⅡ设计,对三峡库区14个玉米地方品种的配合力以及主要性状遗传参数进行了分析。结果表明,‘文峰白玉米’、‘大寨玉米’、‘太阳河白玉米’在单株产量、穗长、穗粗、穗行数、行粒数、百粒重上具有较高的一般配合力。‘文峰白玉米’、‘大寨玉米’在改善株型、提高产量有更为突出的表现。不同性状SCA效应值变幅差异较大,其中单株产量变幅最大,为-25.48%~30.47%。所有性状中,亲本的基因加性效应均对F1性状形成起主导作用;穗长、穗粗、行数等7个性状广义遗传力和狭义遗传力均较高,可在早代进行选择;秃尖长、单株产量的广义遗传力较高,但狭义遗传力较低,不宜过早进行选择。     

转基因抗虫棉核不育系配合力及杂种优势分析

为了分析转基因抗虫棉不育系的配合力和杂种优势。采用6×6NCⅡ交配设计,分析了6份转基因抗虫核不育系与6份陆地棉亲本杂交后,9个性状杂种F1的超父本优势、竞争优势和配合力。结果表明,籽棉产量超父本优势的平均值为19.44%,22个组合具正向的杂种优势;竞争优势的平均值为-8.36%,16个组合出现正向竞争优势。单株铃数的杂种优势最为明显。父本值与F1平均值的相关关系表明,8个性状F1代平均值与父本值的相关性达到极显著水平。经配合力分析,A1、A4、B1、B5等亲本的GCA较好;SCA效应显著的6个性状中,A1×B6、A3×B3等组合的SCA效应均为正值。     

4个谷子不育系主要农艺性状的配合力分析

为测定4个谷子不育系的育种应用潜力,将4个不育系与5个恢复系按NCII不完全双列杂交方式配组,对其杂种F₁的7个主要农艺性状进行配合力分析,结果表明：所有组合的7个主要农艺性状存在显著差异。配合力分析,新选育不育系Y1A、Y2A一般配合力都一般,Y1A有利于选配大穗杂交谷子,Y2A则有利于选配矮秆、子粒饱满的杂交谷子;当地常用的2个不育系张1A、晋1A中,晋1A的一般配合力明显好于张1A,说明晋1A更适合于谷子中晚熟种植区。4个不育系所组配的20个组合中杂种优势不明显,7个主要农艺性状中,晋1A所组配的组合综合性状几乎都最优,组合晋1A×沧239产量最高;Y1A、Y2A和张1A所配组合综合性状高低各不相同。产量前3的组合分别为晋1A×沧239、Y2A×衡优17和张1A×朝阳谷子。分析表明,要想有强优势组合,不仅需要有较高的一般配合力亲本,亲本间还要有较高的特殊配合力。     

Combining ability and correlations for yield components in early generations of potato breeding

A partial diallel set of crosses was made between 14 potato cultivars chosen for their fertility, from those included in a potato breeding programme at the NEIKER – Basque Institute for Agricultural Research. The progeny were grown in completely randomized trials from 1997 to 1999. Performance for yield, tuber number and average tuber weight was analysed in seedling and two clonal generations. Variance estimates due to both general combining ability (GCA) and specific combining ability (SCA) were significant in all generations for all traits under study. However, SCA was more important than GCA in almost all cases. Correlation coefficients among characters, generations, GCA and SCA effects were examined. For tuber yield no relation was obtained between generations; however, average tuber weight and yield were positively associated in all generations. The results indicate that appropriate selection criteria depend strongly on the particular cross. The implication for a breeding strategy are discussed.     

食用向日葵产量与籽粒主要性状配合力及遗传分析

选用4份分枝型恢复系和6份雄性不育系材料作亲本,按照不完全双列杂交（NCII）设计配制24份向日葵杂交组合,对组合的小区产量、单株产量、单盘实粒数、百粒重、籽仁率、籽粒长度和籽粒宽度7个性状的亲本配合力、遗传参数及竞争优势进行分析。结果表明,24份组合的7个性状存在真实性的遗传差异。在亲本不育系一般配合力（GCA）选择的基础上,应注意组合特殊配合力（SCA）的选择,GCA效应值高的亲本育种潜力较大,组配出优势组合的概率大;籽粒长度和籽粒宽度的狭义遗传力较低,分别为7.91%和14.89%,不宜进行早代选择;GCA较高的不育系为亲本A和亲本D,其中亲本A在各性状上均为正向GCA效应值,且在供试不育系中,其GCA效应值最大,其次为亲本D;组合1×A小区产量的SCA效应值及竞争优势最高,为本试验中的最优组合,其他籽粒性状与对照相比也均有提升。     

Combining ability amongst CIMMYT’s early maturing maize (<Emphasis Type="Italic">Zea mays</Emphasis> L.) germplasm under stress and non-stress conditions and identification of testers

CIMMYT (International Maize and Wheat Research Institute) Zimbabwe’s early maturing maize program, which aims to supply seed to approximately 4 million hectares of maize area in eastern and southern Africa, lacks adequate information on heterotic relationships among early maturing germplasm and has no early maturing testers for hybrid development. Open-pollinated varieties (OPVs) and hybrids are the products targeted for this region. Among the hybrids, three-way and double-cross hybrids are desired. Thus the use of single crosses as testers would be an appropriate choice for such a breeding program as one could potentially identify three-way combinations during the early generation test. A twelve-parent diallel was formed and crosses evaluated to identify heterotic groups and single-cross testers. Crosses were evaluated under four different environments in Zimbabwe, two optimal, one low nitrogen stress and one drought stress. P5 (an early maturing line from heterotic group A) and CML 395 (a late maturing inbred line from heterotic group B) were used as reference parents to establish heterotic groupings of germplasm used in the diallel. The single cross (P7/P8) was identified as a potential group A tester because of: (a) co-classification of inbred lines into heterotic group A, (b) good yields-9.8 t/ha (optimal), 3.4 t/ha (low nitrogen) and 2.1 t/ha (drought); and (c) good GCA effects for grain yield (0.49 t/ha) of line P7 while line P8 contributed to reduced height and anthesis-silking interval.     

Genetic variation among cocoa (Theobroma cacao L.) families for resistance to cocoa swollen shoot virus disease in relation to total phenolic content

Phenolic compounds have been suggested as one of the defence mechanisms to cocoa swollen shoot virus disease (CSSVD), but not well studied. Correlation and genetic variation of total phenolic content (TPC) and CSSVD resistance among 53 cocoa families were investigated. Three‐month‐old seedlings of 15 families obtained from an incomplete 6 × 3 NCII mating design, of 24 families from a 3 × 8 NCII mating design and of 14 other families were evaluated for CSSVD and TPC. Plants were inoculated with viruliferous mealybugs carrying the New Juaben CSSV strain (1A) in a gauze house facility. A single seedling randomization within blocks procedure was followed, using the gauze house units as blocks. There were six blocks with five seedlings of each family randomized within each block. Disease severity scores on leaf flushes at the first, second, third and seventh flushes after inoculation were recorded. The TPC before and 3 months after inoculation was also determined. Family effects were highly significant (P ≤ 0.01) for CSSVD severity scores and TPC. Narrow‐ and broad‐sense heritability estimates were low for CSSVD severity but moderate to high for TPC evaluations. Correlations between severity scores and TPC were weak (r = ?0.22 to 0.40) suggesting that the TPC may be of little value in selecting CSSVD resistance varieties in cocoa. Additive effect in terms of significant GCA was important for CSSVD severity scores whereas both additive and non‐additive effects were important for TPC values when the 3 × 8 and 6 × 3 NCII mating designs were analysed. Only clones GU 239/H, GU 290/H and GU 225/V had favourable GCA effects for CSSVD symptom expression indicating their potential for developing progeny with high levels of resistance to CSSVD infection.     

A diallel crossing approach aimed on selection for ripening time and yield in breeding of new strawberry (Fragaria × ananassa Duch.) cultivars

The extension of the ripening season in open field production is of high economic interest for strawberry growers. Therefore, targeted breeding for extreme early or late ripening cultivars with high yield potential is of particular interest. Thirteen strawberry cultivars were crossed in a reciprocal way without selfing, and the 144 resulting F₁ populations were evaluated in a field trial over a period of two consecutive years. The data were analysed using a mixed‐model approach adapted for diallel crossing designs using SAS 9.3. The variability in the crossing approach is mainly based on the general combining ability (GCA) of the cultivars (additive effects). Specific and reciprocal combining abilities (non‐additive effects) appear less important. The highest GCAs for the trait Marketable Yield were found for the cultivars ‘Polka’ and ‘Yamaska’. The trait Earliness is bilateral with significantly low GCAs for early ripening in ‘Clery’ and ‘Daroyal’ and significantly high GCAs for late ripening in ‘Yamaska’ and ‘Florence’. Crosses with these cultivars are likely to deliver populations with both high yield and an extended ripening period.     

Heterotic effects for yield and tuber solids and type of gene action for five traits in 4x potato families derived from interploid (4x-2x) crosses

The degree of heterosis for total tuber yield (TTY) and total solids (TS) in 4x‐2x crosses was estimated by comparing the performance of 12 families with their respective parents in two locations in Wisconsin (USA). The parental 2x clones were Phureja‐haploid Tuberosum hybrids with 2n‐pollen production by first‐division restitution. The general combining ability (GCA) and specific combining ability (SCA) were estimated for TTY, TS, vine maturity (VM), length of tuber sprout dormancy (LD), and tuber eye depth (ED). Family performance for TTY ranged from 74 to 146% at Hancock (E#1) and from 77 to 287 at Rhinelander (E#2) when compared with that of the 4x parent group. For VM, the families were late maturing, but a few precocious ones were identified. For TS, the families had heterosis of 5.1% over the 4x parent group. The families had slightly higher ED values than the 4x parents, but families with values within the commercial range were identified. The family average for LD (54 days) was closer to the 2x group (51 days) than to the 4x group (88 days). The direction and magnitude of the parent‐family relationships were variable. The 4x parent TTY was correlated with progeny in E#1 but not E#2. The 2x parent VM had correlation with the offspring at E#2 but not at E#1. The type of gene action had a trait‐specific expression. Significant SCA and GCA variances were observed, suggesting that additive as well as non‐additive genetic effects were operating. The 4x‐2x crosses were able to generate heterotic families for TTY and TS in combination with other useful traits. However, no promising results were found for LD because of the apparent dominance of the short‐dormancy phenotype. This result indicates the need of additional selection and breeding efforts for some specific traits when using S. phureja‐derived germplasm.     

Genetic combining ability of glucoraphanin level and other horticultural traits of broccoli

Broccoli (Brassica oleracea L., Italica Group) is a source of glucosinolates and their respective isothiocyanate metabolites that are believed to have chemoprotective properties in humans. Glucoraphanin (4-methylsulfinyl-butyl glucosinolate) is a predominant glucosinolate of broccoli. Its cognate isothiocyanate, sulforaphane, has proven a potent inducer of phase II detoxification enzymes that protect cells against carcinogens and toxic electrophiles. Little is known about the genetic combining ability for glucosinolate levels or the types of genetic variation (i.e., additive vs. dominance) that influence those levels in broccoli. In this study, a diallel mating design was employed in two field experiments to estimate combining abilities for glucoraphanin content. The diallel population was developed by crossing nine doubled-haploid (inbred) parents in all possible combinations (36), excluding the reciprocals. Horticultural traits of all entries were assessed on a plot basis. In fall 2001, glucoraphanin concentration of broccoli heads ranged from 0.83 to 6.00 μmol/gdw, and in spring 2002, ranged from 0.26 to 7.82 μmol/gdw. In both years, significant general combining ability was observed for glucoraphanin concentration and total head content, days from transplant to harvest, head weight, and stem diameter. Conversely, no significant specific combining ability was observed for any trait in either year. Results indicate that a given inbred will combine with others to make hybrids with relatively predictable levels of head glucoraphanin as well as, other important horticultural traits. This should allow identification of inbreds that typically contribute high glucoraphanin levels when hybridized with others.Mention of trade names or commercial products in this publication is solely for the purpose of providing specific information and does not imply recommendation or endorsement by the U.S. Department of Agriculture.