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1.
Field experiments were carried out in order to evaluate 4x‐2x families derived from crosses between elite 4x potato cultivars and 2x Tuberosum‐Solanum tarijense and 2x Tuberosum‐Solanum berthaultii clones. Three traits were assessed: total tuber yield (TTY), haulm maturity (HM) and general tuber appearance (GTA). The degree of heterosis of these hybrid families was evaluated by comparison with the respective 2x and 4x parents as well as with seven 4x cultivars. The parental haploid species hybrids derived from S. berthaultii and S. tarijense combined two or more positive horticultural characteristics. Expressed as yield percentage of the 4x parents, the TTY of the families ranged from 53% to 246%. For TTY, the best 4x‐2x hybrid family ranked better than seven out of nine elite 4x cultivars. Some families had GTA scores in the range of the highly selected 4x cultivars. The families, however, were generally later maturing than the 4x parent group. Specific combining ability for TTY and GTA were the only two significant sources of variation observed in this genetic material. Parent‐offspring correlation coefficients were low for all traits, and indicated that parental performance would not be informative at either ploidy level. These results parallel previous investigations with distinct haploid species hybrids where a 4x‐2x breeding scheme was found to be an effective strategy for increasing progeny TTY over the 4x parents. However, the high degree of heterosis for TTY along with good GTA scores observed in certain cross combinations derived from these unadapted 2x species was a somewhat surprising result. Thus far, the importance of these two South American wild potato species, from the potato‐breeding standpoint, has been limited to the fact that they are natural reservoirs of major genes controlling resistance against important diseases and insects. However, the level of performance of some 4x‐2x families in comparative assays with elite cultivars suggests the unanticipated possibility of introgressing genetic factors from S. berthaultii and S. tarijense with positive effects on quantitative traits of horticultural importance along with these major resistance genes.  相似文献   

2.
冉毅东  戴朝曦 《作物学报》1996,22(6):745-749
利用能产生2n配子的二倍体杂种与四倍体普通栽培种(S.tuberosum L.)和四倍体新型栽培种(Neo—tuberosum)进行了2x-2x,4x-2x和2x-4x间的杂交,获得了18个杂交组合的4x杂种家系,将这些家系与其10个4x亲本品种(品系)及对照品种在同一地点进行了连续两年的比较试验。结果表明:4x杂种家系单株平均块茎产量比亲本两年分别高16%和19%;其中最好的6个杂种家系比较好的4个品种(品系)分别高20%和43%;杂种产量的优势主要表现在单株块茎数目的显著增多,但在块茎商品率方面则与4x亲本差异不显著,而且杂种块茎的表现还不如4x亲本及对照品种,这是由于具2n配子特性的2x亲本这些性状较差所致。试验结果还表明杂种的遗传背景愈复杂其杂种优势也愈强,进一步说明马铃薯的产量与遗传异质性(多样性)的强弱可能有明显关系,利用2n配子特性可获得较高的遗传异质性。  相似文献   

3.
The relative value of haploid Tuberosum-Solanum chacoense (TCH) vs. Solanum phureja-haploid Tuberosum (PTH) hybrids as male parents in 4x–2x crosses was estimated under two distinct crop management systems. The first experiment (E#1) was carried out with supplementary irrigation (three times a week) at Hancock-Wisconsin (WI) with 27 families derived from a sub-set of crosses involving 11 tetraploid (4x) cultivars and 10 diploid (2x) clones (3 TCH; 6 PTH; and one TCH-PTH hybrid clone). A second experiment (E#2) was conducted at Rhinelander-WI with the same group of families but it was only rainfed with no supplementary irrigation being provided during the entire course of the assay. For comparison, a complete set of 4x and 2x clones (used as parents) was also planted in each location. Three traits were evaluated in both locations: total tuber yield (TTY), haulm maturity (HM), and plant vigor (PV). Altogether, 18 out of 27 and 10 out of 27 families outyielded the corresponding 4x parents at E#1 and E#2, respectively. Significant differences among all 4x–2x families and among families of the TCH group were observed for TTY at both locations. No difference was found for TTY among families of PTH and [TCH–PTH] groups at each location. A total of 75% and 50% of the TCH families outyielded their 4x parents at E#1 and E#2, respectively. The percentage of families from the PTH group that outyielded their 4x parents at E#1 and E#2 was 83.3% and 25%, respectively. The TCH group had on average lower HM scores than PTH (at both locations) indicating some segregation for earliness. However, the HM values of the 4x–2x families were, in general, higher than those observed for the 4x parents. For PV, the PTH group mean was significantly higher than TCH group only in E#1. The PV values of the 4x–2x families were higher than the 4x-parent group at both locations. Our results indicated that TCH hybrids might be as good parents as PTH to increase the TTY of 4x–2x progenies. In addition, the TCH families displayed a slight higher level of performance under more stressful growing conditions than PTH hybrids as indicated by the assay at Rhinelander. Therefore, selection of genetic materials with potential broad range of adaptation seems to be feasible with both hybrids via the 4x–2x breeding scheme. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

4.
Hybrid breeding is a widely discussed alternative for triticale. Heterosis as well as general (GCA) and specific combining ability (SCA) effects were estimated for eight agronomic traits. The experiment comprised 24 F1 hybrids, produced by a chemical hybridizing agent, together with their six female and four male parents, grown in drilled plots in two locations. In comparison with the mid‐parent values, hybrids averaged a 6.4 dt/ha (10.1%) higher grain yield, 8.4% more kernels per spike, a 6.8% higher 1000‐kernel weight, 9.7% lower falling number (FN) and 4.4% greater plant height. SCA effects for grain yield were significant and ranged from 4.5 to 6.9 dt/ha for grain yield. Together with GCA x location interactions, they explained most of the variation. For 1000‐kernel weight, GCA effects were predominant. SCA and interactions with location accounted for most of the variation in FN, whereas interactions were negligible for plant height. Correlations between mid‐parent and hybrid performance and between GCA and per se performance of parents were tight for all traits except grain yield, which allows for pre‐selection of parental lines. Although the amount of heterosis in triticale at present is closer to wheat than to rye, by selecting parents for combining ability and identifying heterotic patterns, grain yield heterosis of up to 20% appears sufficiently encouraging to embark on hybrid breeding.  相似文献   

5.
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.  相似文献   

6.
The most effective strategy to control Fusarium head blight (FHB), a devastating disease of small‐grain cereals, is breeding resistant cultivars. This resistance study of F1 crosses, F2 and backcross generations of triticale estimates heterosis, general and specific combining ability (GCA, SCA), additive and dominance effects and compares parents with segregating generations. The genetic material consisted of 10 parents with their 45 F1 crosses and of six parents with their 15 F2 progeny and backcrosses to each parent. Genotypes were grown in various environments and artificially inoculated with an aggressive isolate of F. culmorum. FHB was assessed, by visual rating, as the mean of four to five individual ratings of disease development. Heterosis for FHB was of little importance. The correlation between the FHB rating of F1 crosses and their mid‐parent performance was close. GCA was the predominant source of variation, although the significance of the SCA variance also implied non‐additive allelic interaction. The preponderance of additive gene effects is encouraging for increasing resistance by a recurrent selection programme. The relationship between the GCA effect of a parent and its per se performance was close, which gives the possibility of predicting FHB resistance in F1 crosses. Additive effects were predominant in the F2 progeny and also in the backcrosses. Transgressive segregants could not be detected. Searching for them should be postponed to the F3 or later generations.  相似文献   

7.
V. Lind 《Plant Breeding》2000,119(6):449-453
Two diallels were analysed for general combining ability (GCA) and specific combining ability (SCA) to study the resistance of crosses‐between wheat genotypes, advanced to the F5 generation, to Pseudocer‐cosporella herpotrichoides. The parents either carried the resistance‐gene Pch‐1 or had different levels of quantitative resistance, one genotype was susceptible. At medium milk‐ripening, significant effects were‐found for GCA and SCA. GCA effects were the more important. Diallel crosses between genotypes, all carrying Pch‐1, revealed interactions‐of the gene with the genotypic background. Some combinations had a‐higher level of resistance than the best parent. In these populations'CH‐75417’ was involved as a parent. Both ‘CH‐75417’ and ‘F–210.13.4.42’ had significant GCA effects. Crosses between quantitatively resistant parents yielded populations that transgressed both parents. The increased resistance level was associated with ‘Cappelle‐Desprez’, distinguished by its high GCA. In some crosses SCA contributed significantly to an increase in resistance level. Selection for resistance within the best advanced populations is recommended since it‐takes advantage of additive gene action and the high heritability estimates based on ELISA values in plant progenies.  相似文献   

8.
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。  相似文献   

9.
转Bt基因棉杂种优势及性状配合力研究   总被引:45,自引:19,他引:26  
采用NCⅡ设计方法,选用我国构建的Bt(Bacillus thuringiensis)基因棉GK3和美国构建的Bt基因棉新棉33B等Bt基因棉为父本,配制杂交组合,分析了含Bt基因杂交棉组合的性状优势表现及配合力效应。性状优势分析表明,组合的中亲优势和竞争优势明显,皮棉产量中亲优势率达100%,竞争优势率达86.7%,多数品质性状较对照为优,表明转Bt基因棉品系与常规品种间杂种优势利用潜力较大;通径分析表明,在增产因素中,铃重和铃数所起贡献较大;配合力分析表明,父本间和母本间的GCA均方值均达显著或极显著水平,组合的SCA均方值除子、皮棉声量性状外,其余均不显著,在F1性状的遗传中,各性状的加性效应起主导作用;F1的性状表型值与父、母本的GCA呈高度正相关,并达显著水平,表明选配含Bt基因杂交组合时,选择GCA值大的亲本较为可靠。  相似文献   

10.
M. Maris 《Euphytica》1989,41(1-2):163-182
Summary The main aim of the experiment was to study the behaviour of seven long-day adapted clones of Solanum tuberosum ssp. andigena (A) and three varieties of S. tuberosum ssp. tuberosum (T) in an incomplete diallel cross. The four groups of crosses, TxT, TxA, AxT and AxA, held 2, 12, 20 and 21 populations, respectively. Eleven of the intersubspecific crosses were exact reciprocals. Thirty random clones per population were grown as second clonal generation in an incomplete block design with four replications in plots of two plants per clone in 1980, the parents included in many plots. Data were recorded on ten characters.The results showed that group TxA gave the highest tuber yield and AxT the second highest. The F-values indicated highly significant genotypic effects for all characters in all populations. The mean genotypic coefficients of variation (GCV), were the highest for group AxA for all characters. The ANOVA, based on population means showed significant mean squares for general combining abilities (GCA) and for differences of reciprocalls for all characters; the specific combining ability (SCA) mean squares were significant only for date of emergence, plant height and haulm type. Almost all GCA effects of the parents were significant positive or negative. Several populations showed also significant SCA effects. The correlations between the GCA effects and the parental values were of about the same magnitude as the heritabilities; those between the population means and the midparental values were slightly lower.Compared to the midparental values, most populations showed significant positive heterosis for date of emergence, haulm type, number of tubers and under water weight; all populations had significant negative heterosis for mean tuber weight and nearly all for plant height and general impression. All populations from groups TxT and AxA had significant negative heterosis for tuber yield and so had 13 out of the 20 populations from group AxT, while seven of the 12 from group TxA showed significant positive and four significant negative heterosis. The average heterosis for tuber yield of group TxT was –11%, of TxA 3.4%, of AxT–9% and of AxA–18%. The highest mean tuber yields were obtained from crosses with a very high yielding A-parent as female, while the heterosis was negative. Though significant differences between the 11 reciprocals occurred for all characters, consistent differences occurred only for tuber yield. Averaged over the 11 crosses the TxA populations outyielded their exact reciprocals by 10.7%. For the highest tuber yields in A-T crosses, therefore, the tuberosum cytoplasm seems to be preferable. By contrast for a high male fertility the andigena cytoplasm is preferable.  相似文献   

11.
选用农家种改良过的6个食葵细胞质雄性不育系和4个优良的分枝型恢复系为亲本,按NCⅡ遗传交配设计,配成24个F1杂种,研究了9个主要经济性状,即株高、茎粗、生育期、盘径、单盘总粒数、单盘实粒数、结实率、百粒重、单株产量的配合力及杂种优势表现。结果显示:(1)不育系中有8个性状,恢复系中有7个性状的一般配合力差异达显著或极显著水平;有4个性状的特殊配合力差异达到显著或极显著水平;(2)株高、茎粗、生育期、盘径、百粒重等5个性状主要受基因的加性效应控制;单盘总粒数、单盘实粒数、结实率、及单株产量等4个性状则受基因的加性效应和非加性效应共同影响;(3)从GCA分析看,参试的不育系以A6最为理想,A2次之;恢复系则以C3最为理想。从SCA分析看,组合A2C1单株产量效应值最高;(4)杂种优势分析表明,大部分经济性状存在杂种优势,甚至相当一部分存在超亲优势,并且这些优势都是可利用的,F1多倾向于早熟、粗壮、高杆、大盘、多粒亲本。  相似文献   

12.
The purpose of this research was to evaluate the combining ability of six local Iranian and one imported cantaloupe cultivar. Heritability of traits was estimated using a half‐diallel mating design. Seven parents and their crosses were evaluated in 2013 and 2014. The greatest general combining ability (GCA) for yield and fruit number was for “Rish‐baba” (0.53 kg/plant and 0.3, respectively). The cultivar “Ananasi” had the highest GCA for fruit weight and soluble solids content (SSC) (0.088 kg and 1.4, respectively). “Ananasi” presented the highest GCA values for fruit firmness, chlorophyll a and b and carotenoid content, as well as the highest total chlorophyll content. The cross Garmak × Rish‐baba showed the highest specific combining ability (SCA) for yield with heterosis value of 99%. High heritability estimates for SSC (0.52), flesh thickness (0.61) and concentration of chlorophyll a (0.7) were obtained. Although there were significant SCAs for yield, the parents are suggested to be improved prior to hybrid development. The parent “Ananasi” appears to be a suitable donor in breeding programmes.  相似文献   

13.
Development of hybrids is considered to be a promising avenue to enhance the yield potential of crops. We investigated (i) the amount of heterosis observed in hybrid progeny, (ii) relative importance of general (GCA) versus specific (SCA) combining ability, and (iii) the relationship between heterosis and genetic distance measures in four agronomic traits of spring bread wheat. Eight male and 14 female lines, as well as 112 hybrids produced in a factorial design were grown in replicated trials at two environments in Mexico. Principal coordinate analysis based on Rogers' distance (RD) estimates calculated from 113 SSRs revealed three different groups of parents. Mid-parent heterosis (MPH) for grain yield averaged 0.02 t ha−1 (0.5%) and varied from −15.33% to 14.13%. MPH and hybrid performance (F1P) were higher for intra-group hybrids than for inter-group hybrids, with low values observed in inter-group crosses involving two non-adapted Chinese parents. Combined analyses of variance revealed significant differences among parents and among hybrids. Estimates of GCA variances were more important than SCA variances for all traits. Tight correlations of GCA with line per se performance, and mid-parent value with F1P were observed for all traits. In contrast, correlations of MPH with RD and coefficient of parentage were not significant. It was concluded that the level of heterosis in spring wheat was too low to warrant a commercial exploitation in hybrids. SSRs proved to be a powerful tool for the identification of divergent groups in advanced wheat breeding materials.  相似文献   

14.
陆地棉优异种质间的杂种优势和配合力分析   总被引:22,自引:6,他引:22  
采用 NC 交配设计 ,对包括转基因抗虫棉、常规棉、柱头外露种质系、彩色棉等 1 0份陆地棉优异亲本交配后 ,杂种 F1的 1 0个性状的杂种优势和配合力进行了分析。结果表明 ,皮棉产量超高优势的平均值为 - 2 .91 % ,1 0个组合具正向的杂种优势 ;中亲优势的平均值为 2 2 .45 % ,2 1个组合均具有正向的中亲优势 ;竞争优势的平均值为 -1 4.2 1 % ,4个组合出现正向竞争优势。其它产量性状中单株铃数的杂种优势最为明显。纤维品质性状 ,2 .5 %跨长的优势明显 ,麦克隆值的负向优势明显。高亲值、中亲值和低亲值与 F1平均值的相关关系表明 ,多数性状 F1代平均值与中亲值和低亲值相关性密切。配合力上 ,新棉 33B、680 2、94AP1 4、96- 67、 99- 1 6和 99- 5 5表现较显著的GCA效应 ;SCA效应显著的 7个性状中 ,A1 B3、A4B1、A5 B3等组合有 6个性状的 SCA效应值为正。  相似文献   

15.
The heterosis and combining ability for plant height and its components of hybrid wheat were investigated in an incomplete diallel experiment including 5 CMS lines and 4 restorer lines. The results showed that heterosis (HS) and heterobeltiosis (HBS) occurred in plant height (PH) and length of the first internode (LFI), second internode (LSI), third internode (LTI), basal internode (LBI) and the spike (LS) of hybrids, but their values varied among crosses and characters; the HS and HBS of LBI were larger than those of other characters, the HS and HBS of LSI and LTI contributed a lot to those of PH. There were significant relationships between internode lengths and PH for specific combining ability (SCA) and general combining ability (GCA), and among lengths of the adjacent internodes for SCA and/or GCA effects. However, the relationships of LS with the lengths of internodes and PH were insignificant for GCA, SCA, HS and HBS. The SCA effects were more important than GCA effects for LFI, the reverse was true for LSI, LTI, LS and PH, and the SCA effects was nearly equal to the GCA effects for LBI. So, LFI was mainly influenced by non-additive effect of genes, while LSI, LTI, LS and PH were mainly controlled by additive gene effects, LBI was controlled equally by additive and non-additive effects of genes. The genes that control the length of specific internode not only affect PH, but also the length of the adjacent internode. The genetic system in charge of lengths of internodes and plant height is independent of that for length of spike. Thus, it is possible to develop new wheat cultivars or hybrid combinations having long spike but dwarf plant height. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

16.
杨加银  盖钧镒 《作物学报》2009,35(4):620-630
2003-2005年以选自黄淮地区及美国的8个大豆重要亲本品种(系)及其组配的28个双列杂交组合为材料, 分析大豆亲本间的产量杂种优势及其配合力, 探讨高优势组合的遗传基础, 包括杂种优势与亲本系数、SSR标记遗传距离的相关。结果表明: (1)黄淮地区大豆亲本间存在产量超亲优势, 平均20.39%, 组合间差异甚大, 变幅–5.34%~76.88%, 优选出豫豆22×晋豆27、淮豆4号×晋豆27、诱变30×蒙90-24, 超亲优势分别为76.88%、29.90%和34.42%, 超标率均在25.00%以上, 晋豆27和诱变30为优秀亲本材料。单株荚数及单株粒数的优势和产量优势相对一致;(2) 大豆亲本间产量杂种优势既与双亲一般配合力之和及特殊配合力有关, 又不完全相关。高优势高产组合的亲本产量配合力特点为亲本之一具有较高的一般配合力, 或双亲具有较高的一般配合力之和, 兼有较高的特殊配合力。单株荚数和单株粒数的情况和产量一致;(3) 按亲本系数聚类和按SSR标记遗传相似系数聚类揭示的8个亲本间的遗传关系相对一致, 均分为两组, 一组包含6个黄淮中、南部品种(系), 另一组包含1个山西和1个美国品种。要获得高优势高产组合, 亲本间必须具有一定的遗传距离, 但遗传距离大并不一定都高产高优势, 还有其他因素决定杂种优势。  相似文献   

17.
Ga糯玉米自交系的配合力分析与评价   总被引:1,自引:0,他引:1  
摘要:利用不完全双列杂交NCⅡ设计,以3个经遗传改良的Ga糯玉米自交系为父本,与8个糯玉米自交系进行杂交。对24个杂交组合进行农艺性状鉴定,分析Ga糯玉米自交系主要农艺性状的配合力效应。结果表明,父、母本各性状的一般配合力和特殊配合力效应均达极显著差异。Ga糯玉米自交系具有良好的配合力,其中,CM327的一般配合力效应比较高,其组配的杂交种在产量、穗长、行粒数等性状上具有明显优势,具有很好的杂优利用潜力。Ga糯玉米自交系的选育利用,有助于糯玉米种质的扩增与杂种优势的利用。  相似文献   

18.
Heterosis and combining ability studies were conducted on selected chickpea genotypes in order to (1) acquire an understanding of the predominant type of gene action governing biomass (BY) and harvest index (HI), (2) estimate the magnitude of heterosis, (3) estimate combining ability effects and (4) assess correlations between per se performance and general combining ability (GCA) of the parents under a drought-prone, rainfed short-duration environment (SDE) where BY is considered to be an important trait for enhancing chickpea productivity. The experimental material comprised 30 F1s obtained by crossing ten adapted genotypes as females to three testers as males in a line × tester design. The GCA variances were significant and of a high magnitude, while specific combining ability (SCA) variances were non-significant, indicating the predominant role of additive gene action on BY and the HI. A large number of crosses showed positive mid-parent heterosis (MPH) and better-parent heterosis (BPH). The average MPH and BPH for BY was 22.36 and 12.65, respectively, and the average MPH and BPH for the HI was 2.22 and −0.92, respectively. The higher magnitude of the MPH and BPH recorded for BY indicated that the scope for increasing the HI in chickpea in a drought-prone, SDE is limited and that further increases in productivity have to come mainly through enhanced BY. The majority of the heterotic crosses involved poor × good combiners. This study demonstrates that in order to achieve greater progress in improving BY and the HI in chickpea, the selection of parents should be based on per se performance as well as combining ability and heterosis.  相似文献   

19.
Families and cultivars derived from three breeding strategies [the conventional 4x-4x (intra-Tuberosum), the interploid 4x (Tub)-2x (Phureja-haploid Tub), and 4x (Tub)-4x (diplandrous tetraploid-DTO)] were evaluated under short-day conditions in Brazil. Two 4x-4x (intra-Tub) cultivars (`Bintje' and `Delta') were used as standards. The 4x-2x (FDR) and 4x-4x (DTO) strategies were equivalent for all traits but they presented superior performance when compared to the 4x-4x (intra Tub) scheme(as a group) for total tuber yield (TTY), commercial yield (CY), and plant vigor (PV). No differences among breeding schemes were observed for three other traits: eye depth (ED), plant uniformity (PU), and haulm maturity (HM). As a group, the 4x-2x (FDR) and 4x-4x (DTO) strategies were similar to the two standard cultivar for all traits but HM. However, eight families [six 4x-2x (FDR) and two 4x-4x (DTO)] had significantly superior performance for TTY when compared with the standard cultivars. For CY, the best 4x-4x (DTO) and the best 4x-2x (FDR) families outyielded `Bintje' by161% and 128%, respectively. No major differences were observed between breeding schemes for TTY and CY when comparing families derived from one single cultivar (`Chiquita') as 4x female parent. However, superior families, based upon multi trait selection criteria, could be obtained only with the 2n-pollen-based strategies. It was possible to select high yielding 4x-2x (FDR) and 4x-4x (DTO) families with favorable trait combinations (e.g., high yielding with ED scores similar to the standards). Individual DTO clones selected within these families may represent outstanding parental materials for crosses with tropical-adapted commercial cultivars. This initial comparison of progenies and cultivars derived from these breeding strategies suggests that 4x-2x (FDR) and 4x-4x (DTO) schemes could be viable alternatives to the conventional 4x-4 × crosses also in tropical/subtropical areas of the world. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

20.
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。  相似文献   

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