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1.
为了培育既抗除草剂、综合性状又优良的杂交水稻组合,将3份抗除草剂衍生恢复系（华84EP-1、2、3）与5份不育系（红香2A、Y58S、广占63-4S、华1015S、天源6S）配组,对亲本、杂交组合的除草剂抗性和10个主要农艺性状（单株产量、结实率、千粒重、生育期、株高、有效穗数、着力密度、穗总粒数、穗实粒数、穗长）的配合力效应进行了分析。结果表明,所选育的恢复系的除草剂抗性接近完全(>96%),利用苗期喷施农达可有效地提高杂交品种纯度;恢复系、不育系的一般配合力分别在5个性状（结实率、生育期等）、7个性状（结实率、千粒重等）上达到了显著差异;杂交组合的特殊配合力仅在生育期上达到了显著差异。杂交组合中比对照增产最高的分别是天源6S/华84EP-1、红香2A/华84EP-3和华1015S/华84EP-1。因此,利用抗除草剂恢复系配制水稻杂交组合不仅可以提高品种纯度,也可以培育出强优势组合。 相似文献
2.
The aim of this study was to estimate the general combining ability of the parents and specific combining ability of hybrids
considered for the development of high yielding and better quality cultivars. Seventeen genotypes and 52 F1 hybrids obtained by crossing 4 lines and 13 testers in line × tester mating system during 2003 were sown in randomized complete
block design in 2004. Line × Tester analysis revealed significant GCA and SCA effects for all the traits except fibre elongation.
Preponderance of non-additive gene action was obtained for seed cotton yield per␣plant and majority of its component traits
including fibre traits. Among the parents: PIL-8 for days to 50% flowering, CCH-526612 for boll weight, CITH-77 for number
of open bolls per plant and CNH-36 for seed cotton yield per plant were detected with higher general combining ability. Parent,
CCH-526612 for 2.5% span length, fibre strength and fibre elongation and AKH-9618 for micronaire value, fibre strength and
fibre elongation were good combiners for fibre quality traits. The F1s achieved high seed cotton yield by producing more number of open bolls. The high yielding hybrids with acceptable fibre
quality traits were: CISV-24 × LH-1995, H-1242 × PIL-8 and RS-2283 × SGNR-2 deducted with significant SCA effects for seed
cotton yield and fibre characteristics; 2.5% span length and fibre strength. These cross combinations involved at least one
parent with high or average GCA effect for a particular trait. 相似文献
3.
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. 相似文献
4.
陆地棉显性无腺体品系杂种优势及配合力研究 总被引：5，自引：0，他引：5
以７个显性无腺体陆地棉品系和４个常规品种（系）为材料，按ＮＣＩ设计，对２８个组合的杂种Ｆ１进行了分析。结果表明。杂种Ｆ１具有明显的优势，２８个组合所研究的１５个性状中全部具有中亲优势，６个性状具有高亲优势，４个性状具有竞争优势；配合力分析的１１个性状中，株高、衣分、纤维长度和麦克隆值主要受基因加性效应控制，而子棉产量、皮棉产量、单株铃数、铃重和子指等性状同时受基因加性和非加性效应作用，显无０７３是丰产的显性无腺体品系，而显无２６０是较好的优良品系，组合显无０７３Ｘ泗棉２号在重要性上表现较好。 相似文献
5.
陆地棉配合力与杂种优势、遗传距离的相关性分析 总被引：6，自引：2，他引：4
用10个陆地棉亲本进行不完全双列杂交,共配置了45个组合,计算亲本的一般配合力（GCA）、特殊配合力(SCA)、杂种优势,并结合SSR标记研究了陆地棉亲本配合力与杂种优势、遗传距离之间的相关关系。配合力分析发现,10个亲本的一般配合力和特殊配合力存在显著或极显著差异。分析亲本配合力、杂种优势和遗传距离的相关性发现,子棉产量、皮棉产量、衣分的一般配合力和杂种优势呈显著或极显著相关,纤维长度、比强度、麦克隆值、株高、果枝数、单株铃数、铃重、子棉产量、皮棉产量、衣分的特殊配合力和杂种优势均呈极显著正相关,而与遗传距离相关均不显著。单株铃数、铃重、子棉产量、皮棉产量、衣分的杂种优势与遗传距离均为正向显著或极显著相关。在育种实践中这些显著或极显著相关的性状可能具有较高的改良潜力。 相似文献
6.
Summary To determine the levels of heterosis in F1 hybrids, four current pea (Pisum sativum L.) cultivars from southern Australia were used as female parents and crossed with 18 introduced genotypes. The 22 parents, 72 F1 hybrids and, depending on the environment, either 54 or all 72 F2 families were grown in replicated plots in four environments. Grain yield, total dry matter, harvest index, branches per plant, pods per plant, seeds per pod, hundred seed weight, plant height, onset of flowering and flowering periods were evaluated. For both the F1 and F2 generation, heterosis was determined as the superiority over the mid-parent and also over the better parent. In addition, the superiority over the best commercial cultivar was calculated. Most hybrids were higher yielding than their mid-parent but were less stable in yield across environments. Four F1 hybrids were significantly higher yielding than the best parent, by up to 26%. There were significant correlations between F1 hybrid and mid-parent value for plant height, pods per plant and hundred seed weight but not for yield. Overall, grain yield heterosis was mainly due to more pods per plant in the hybrids. The level of heterosis for yield in a poor yielding environment was higher than that in a high yielding one. Both additive and non-additive gene effects were important in the expression of all studied traits. The average level of heterosis for grain yield and total dry matter in the F2 population was half of that in F1 hybrids. The low level of inbreeding depression from the F1 to the F2 generation suggested that epistatic gene action also contributed to the expression of grain yield. Some F2 populations maintained the high yield levels of the corresponding F1 hybrids. 相似文献
7.
Genetic analysis of rapeseed self-incompatibility lines reveals significant heterosis of different patterns for yield and oil content traits 总被引：7，自引：0，他引：7
Self‐incompatibility is one of the most effective approaches to utilizing heterosis in oilseed rape around the world. To evaluate the heterosis of double low self‐incompatibility, the possibility of combining seed yield and oil content, and the genetic effects of parents on their hybrid progenies, a 2‐year field trial using a 3 × 22 NC II mating design was conducted during the 1999‐2001 growing seasons in Wuhan, China. Significant differences in seed yield per plant and seed oil content were observed among the F1 hybrids and between F1 progenies and their parents. However, the heterosis for seed yield per plant was much greater than that for seed oil content. Mid‐parent heterosis and high‐parent heterosis of seed yield per plant ranged from 5.50 to 64.11% and from –2.81 to 46.02%, while those of seed oil content ranged from –1.55 to 7.44% and –3.61 to 6.55%, respectively. Non‐additive genetic effects were a major mechanism that accounted for the yield heterosis in addition to additive effects. In contrast, seed oil content heterosis was mainly dependent on an additive genetic effect. General combining ability (GCA) determined the stability of hybrid cultivars. In hybrid breeding, parental materials might be selected by the sum of GCAs and variances of special combining abilities (SCAs) of female and male parents for traits affected by both additive and non‐additive effects, and by the sum of GCAs of two parents for traits controlled mainly by additive effects. Primary branches and their siliques were the most important yield traits. 相似文献
8.
Miriam Fernández-Calleja Ana M. Casas Antonio Pérez-Torres Maria Pilar Gracia Ernesto Igartua 《Plant Breeding》2020,139(2):317-327
Two dominant, closely linked and complementary genes, Btr1 and Btr2, control rachis brittleness in barley. Recessive mutations in any of these genes turn the fragile rachis (brittle) into a tough rachis phenotype (non-brittle). The cross of parents with alternative mutations in the btr genes leads to a brittle F1 hybrid that presents grain retention problems. We evaluated rachis fragility through a mechanical test and under natural conditions, in F1 crosses with different compositions at the btr genes. Brittleness was significantly higher in Btr1btr1Btr2btr2 crosses compared to hybrids and inbred parents carrying one of the mutations (btr1btr1Btr2Btr2/Btr1Btr1btr2btr2). This fact could jeopardize the efficient harvest of hybrids bearing alternative mutations, reducing the choice of possible crosses for hybrid barley breeding and hindering the exploitation of potential heterotic patterns. Furthermore, non-brittle hybrids showed higher brittleness than inbreds, suggesting the presence of other dominant factors affecting the trait. In conclusion, this work encourages a deeper study of the genetic control of the rachis brittleness trait and urges the consideration of rachis tenacity as a target for hybrid barley breeding. 相似文献
9.
Mandalapu Pallavi Pulluru Sanjana Reddy Chamarthy Venkata Ratnavathi Kancharla Venkata Radha Krishna 《Plant Breeding》2023,142(3):345-356
Pearl millet occupies an important place in attaining nutritional security in marginal areas; however, as it develops off-flavours, it is less preferred by food industry. The objective of the current study was to determine the variations in rancidity-related traits and estimate the combining ability of inbreds and hybrids for these traits under varied environmental conditions. In this study, 32 hybrids were developed from eight lines and four testers using line × tester mating design and evaluated along with parents and checks 86M86 and HHB 67 for yield and rancidity-associated traits in three environments. The hybrids L7T2 and L6T1 are identified as promising hybrids for grain yield and rancidity. Higher variance due to specific combining ability and predictability ratio for grain yield and rancidity-associated characters indicate the predominance of non-additive gene action. The tester T1 recorded a significant negative GCA effect with low alcoholic acidity. A significant and positive SCA for grain yield was observed in L3T1 and L7T2, whereas for rancidity in L5T4. Alcoholic acidity showed a significant positive association with 1000 seed weight, lipase and lipoxygenase in parents and negative association with 1000 seed weight in hybrids. 相似文献
10.
In wheat, the possibility of introducing F1 seed into practical agriculture has been greatly enhanced by the discovery of effective chemical hybridising agents (CHAs).
Although some technical and economic problems concerning the use of CHAs for large-scale production of F1 seed remain to be solved, a first group of F1 hybrids has been submitted for registration in several European countries i.e., France, England and Italy. Combining ability
for grain yield and several agronomic and quality traits was studied in an eight-parent diallel cross. Highly significant
combining ability effects were observed for all the traits while specific combining ability effects were statistically significant
for grain yield, plant height, heading time and Chopin alveograph parameter P. The level of genetic diversity between parents
as estimated using molecular markers is considered a tool for predicting the hybrid performance and heterosis of crosses.
To explore this possibility, RFLP and RAPD markers were used to predict the performance of hybrids obtained from diallel and
top crosses. The performance of the hybrids was determined in replicated plot trials sown at normal seed density in several
locations. Coefficient of parentage (rp), based on pedigree information for all the pairwise combinations of the parents ranged
from 0.01 to 0.34. The parents were assayed for random amplified polymorphic DNA (RAPD) with 87 primers which generated 304
polymorphic bands. Genetic similarity between parents, estimated on the basis of common bands using the Jaccard's similarity
coefficient (J), ranged from 0.25 to 0.57. Correlation between parental diversity and hybrid performance was generally weak.
A positive trend is observed in the yield potential of the hybrids produced in Italy in the last 10 years. In fact among the
first set of hybrids produced by random crossing of the available cultivars, none produced 10% more than the checks whereas
the last generation of hybrids includes combinations yielding 15% more than the best standards. Our results clearly indicate
the need to develop specific strategies in order to identify and/or to select parental lines with a high level of general
combining ability (GCA) and specific combining ability (SCA). The information regarding the genetic diversity of the parental
lines do not appear helpful for predicting F1 performance.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
11.
甘蓝型油菜杂交种中雄性不育母本假杂种是影响种子纯度的关键。为了探索一种能准确鉴定油菜杂交种中母本假杂种的方法,利用CTAB小样法分别提取油菜F1杂种种皮和幼苗的总DNA,进而筛选种皮与幼苗的SSR谱带存在差异的引物,并用于鉴别杂交种制种样品中母本基因型假杂种。结果表明：F1杂种种皮的SSR电泳谱带与其母本相同,利用筛选到的多态性SSR引物对2个国审品种的6份杂交制种样品中母本基因型假杂种鉴定的结果与田间单株鉴定吻合率达98%以上,说明利用F1杂种种皮与幼胚存在多态性的SSR标记鉴定杂交种的母本基因型假杂种是可靠的。该技术方法可以克服目前油菜杂交种SSR纯度鉴定对亲本的依赖,为种子生产、管理和经营部门种子纯度质量的有效监控提供技术参考。 相似文献
12.
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
13.
Utilization of Genetic Variability of Resynthesized Rapeseed 总被引：3，自引：0，他引：3
K. Kräling 《Plant Breeding》1987,99(3):209-217
The performance of single cross hybrids between resynthesized (resyn.) genotypes and varieties of rapeseed was tested in microplots. The results revealed strong, genetic differences between the artificially synthesized rapeseed forms for all the characters investigated, as well as for g.c.a. values. In particular, hybrids with resyn rapeseed exhibited a vigorous vegetative growth. It should therefore, be beneficial to use resyn forms directly in fodder rape breeding programmes. Disturbances in fertility of the resyn material resulted in a low number of seeds per pod and consequently in an inferior seed yield as compared to the varieties, although some high yielding combinations were also identified. Three-way hybrids with a 25% genome share of the resyn rapessed reached only lower vegetative performance as compared 10 the hybrids with a 50% resyn genome but their performance in generative traits was general superior- In respect to seed yield some progenies of three-way hybrids showed a higher plot performance than even the high yielding varieties. A further comparison between single-cross combinations of resyn × variety on the one hand and variety × variety on the other hand demonstrated that resyn genotypes, due to a distinct apical dominance, exhibited a pronounced expression of characters measured on the main stem. But in total, ii is evident from the present findings that any hybridization with this resyn material does not promise immediate short-term varietal improvement. 相似文献
14.
The combining abilities for physical-quality traits in peanut were examined to understand the type of gene action governing
these traits, and to identify peanut genotypes suitable for use as parents in breeding for quality improvement. The F1 hybrids including reciprocals from a six-parent diallel cross along with the parents were evaluated in a randomised complete
block design. Data were recorded on five quality traits in peanut viz., shelling outturn, 100-pod weight, 100-seed weight, Count and proportion of sound mature seeds. Substantial genetic variability
was observed among the hybrids for the traits studied. Diallel analysis indicated that expression of majority of the quality
traits is regulated predominantly by additive gene action suggesting possibility of early-generation selection, while non-additive
gene action also plays an equally important role in the control of seed size. Significant reciprocal effect for all the traits
denoted role of maternal parent in the expression of quality traits and importance of parental selection in quality breeding.
Genotypes ICGV 86564 and TPG 41 were good combiners for seed size, while J 11 was a good combiner for improvement of shelling
outturn and proportion of mature seeds. Association between general combining ability (GCA) effects and mean performance suggested
that the performance per se of the genotype should be a good indicator of its ability to transmit the desirable quality attributes
to its progenies. Though performance of crosses was found to be independent of parental GCA status, it is evident that at
least one of the parents used in hybridisation should have large pods and seeds for obtaining better segregants. 相似文献
15.
The improvement of the nutritional value and the stability properties of rapeseed oil is partly hindered by the lack of information on the genetic control of tocopherols. The objectives of this investigation were to characterize the inheritance of tocopherols by using two factorial mating designs (North Carolina Design II, NCII). The first (NCII‐A) was produced with two sets of nine parents each, one selected for high and the other for low total tocopherol contents. In the second (NCII‐B), each set consisted of six parents, which were either high or low for the α/γ‐tocopherol ratio. Parents and F1 hybrids from both experiments were tested under field conditions in 1998 and 1999 using a completely randomized design with two replications. Only small differences were detected between mean values of parents and F1 hybrids. General combining ability (GCA) variation in both experiments was highly significant (P < 0.01) for all tocopherol traits. Significant specific combining ability (SCA) effects were only detected for a‐tocopherol in NCIIA and therefore for the α‐/γ‐tocopherol ratio. These results indicate that tocopherol contents and composition are controlled mainly by genes with additive effects. Interactions of F1 hybrids and GCA effects with the environment were significant for only tocopherol contents and not for tocopherol composition. 相似文献
16.
Genetic analysis of mechanisms associated with inheritance of resistance to sheath rot of rice 
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下载免费PDF全文 Simon Martin Mvuyekure Julia Sibiya John Derera John Nzungize Germain Nkima 《Plant Breeding》2017,136(4):509-515
Understanding genetic mechanisms controlling inheritance of disease resistance traits is essential in breeding investigations targeting development of resistant genotypes. Using North Carolina design II, 32 F1 hybrids were generated by crossing eight susceptible to four resistant parents and submitted for field evaluation. The analysis of general and specific combining ability (GCA and SCA) indicated involvement of additive and non‐additive gene action controlling inheritance of horizontal resistance to sheath rot of rice. High GCA/SCA ratio and high heritability estimates revealed additive effects and were more predominant than none additive ones. The level of dominance indicated dominant genes was more important than recessive genes. Estimates of GCA and SCA analysis suggested that crop improvement programmes should be directed towards selection of superior parents or good combiners, emphasizing on GCA. As far as source of resistance is concerned, most promising genotypes were Cyicaro, Yunertian and Yunkeng. The predominance of additive genetic effects together with the relevance of dominant genes suggested possibilities of improving the resistance by introgression of resistance genes through recurrent selection coupled with phenotypic selection. 相似文献
17.
Hybrid varieties have not become commercially successful in perennial and self‐incompatible forage crops because of their severe inbreeding depression and/or ineffectiveness in commercial seed production. Here, a modified synthetic variety (MSV), a breeding method for forage crops is proposed, where specific combining ability (SCA) is exploited in a way different from that in hybrids. As Syn‐l seeds from only two of its parental clones are used to produce its Syn‐2, its performance in Syn‐2 partially depends on the SCA between the two seed parents. The inbreeding coefficient of MSVs can be as low as that of conventional synthetic varieties sold today. To evaluate its advantages, 15 modified synthetic strains (MSSs) of timothy were developed from a set of Syn‐l seeds of a conventional synthetic strain (CSS) having six parental clones. An MSS (Syn‐2) showed a yield level equivalent to and a disease score significantly lower than the CSS (Syn‐1) in a field test. The diallel crossing analysis implied that the SCA effects are influential for yield, and that MSV or other SCA‐exploiting breeding methods have the potential to improve the yield level of timothy effectively. 相似文献
18.
Elizanilda Ramalho do Rêgo Mailson Monteiro do Rêgo Fernando Luiz Finger Cosme Damião Cruz Vicente Wagner Dias Casali 《Euphytica》2009,168(2):275-287
The aim of this work was to estimate the general and specific combining ability of peppers by measuring fruit quality and yield traits. This experiment was carried out on the garden field from Universidade Federal de Viçosa (UFV), Minas Gerais State—Brazil. Eight lines of Capsicum baccatum belonging to the UFV Horticultural Germplasm Bank were chosen based on their broad genetic and phenotypical background variation and then they were crossed in a complete diallel way. The F1 seeds of the 56 hybrids and eight parents were planted in the field in a randomized complete block design. The data were submitted to ANOVA and the means were grouped by Scott–Knott test (P ≤ 0.01). Significant variation for fruit quality and yield components was observed among parents and F1 generation. Analysis of variance for the combining ability showed that GCA effects exhibited significant difference and SCA effects of the crosses were significant, except for the height of first bifurcation. For almost all characters both additive and non-additive effects influenced the performance of hybrids. 相似文献
19.
A comparison of cytoplasmic and chemically-induced male sterility systems for hybrid seed production in wheat (Triticum aestivum L.) 总被引：1，自引：0，他引：1
A comparison of two male sterility systems was carried out in wheat for hybrid seed production and hybrid performance. Seventeen
hybrid combinations based on Triticum timopheevi cytoplasm were compared with their genetically equivalent CHA-facilitated combinations. The same set of restorer lines was
used as parents in CMS- and CHA-based hybrids to maintain genetic equivalence. In the first experiment aimed at study of female
line behavior and crossed seed production, the CHA treated lines showed significantly shorter heights whereas CMS lines were
similar to the control. The two systems were equally effective in sterilizing rate. The outcrossing percentage of the CMS
lines was almost twice that of the CHA treated lines. Thousand-grain weight of the crossed seeds on CMS lines was greater
than on the CHA treated lines and control. On average, the germination percentage of seeds on CMS lines was double that of
the CHA treated lines and the percentage of effective outcrossed seeds in CMS lines was 3 times more than that from CHA treated
lines. The second experiment was conducted to examine the yield performance of the hybrids derived from the two systems of
male sterility. A total of 40 entries including 20 hybrids and 20 parents were evaluated in the experiment. The mean grain
yield of the CMS-based hybrids was greater than that of the CHA-based hybrids,the B and R lines. All the CMS-based hybrids
showed significantly higher grain yields than their better parents whereas all the CHA-based hybrids, except two,showed no
significant yield increases over their better parents. Possible reasons for differences in CMS- and CHA-based hybrid performance
are discussed.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
20.
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。 相似文献