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1.
Summary Six of 16 F1 hybrids from diverse crosses of crisphead lettuce with butterhead, cos or other crispheads significantly outyielded their respective better parent. Four were crosses between crisphead and cos parents, one was a butterhead × crisphead cross and one, a winter crisphead × winter crisphead cross. This latter hybrid plus one other also proved heterotic in a subsequent trial of ten crosses involving five winter crisphead parents, with yield excesses over better parent of 16 and 19%. It appeared significant that the heterotic crosses were given by parents of dissimilar origin. Trials of F2 segregants from one of these heterotic hybrids enabled predictions to be made for 10.2 to 24.1% yield increases over better parent by the retention and clonal multiplication of the 10% highest yielding selections. Heterosis demonstrated in these trials may constitute the first reported cases in lettuce. 相似文献
2.
Summary C-banding andin situ hybridization were used to determine the chromosomal constitution of the greenbug-resistant germplasm GRS 1204. The results showed that this line had the radiation-induced non-homoeologous wheat-rye translocation chromosomes T2AS-1RS·1RL and T2AL·2AS-1RS. C-banding analysis further revealed the presence of a wheat-Agropyron elongatum translocation chromosome T1BL·1BS-3Ae#1L in line GRS 1204, that was derived from Teewon. The greenbug resistance of line GRS 1204 is similar to that of line GRS 1201 that was earlier shown to have the greenbug resistance geneGb6 located on the 1RS arm of the wheat-rye translocation chromosome T1AL·1RS. BecauseGb6 in line GRS 1204 is present on one of the non-homoeologous translocation chromosomes, agronomically line GRS 1201 should be the better adapted source ofGb6 resistance and be used in cultivar improvement. 相似文献
3.
Heterosis and combining ability for grain yield and other agronomic traits in winter triticale 总被引：1，自引：0，他引：1
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
4.
Glauco Vieira Miranda Leandro Vagno de Souza João Carlos Cardoso Galvão Lauro José Moreira Guimarães Aurélio Vaz de Melo Izabel Cristina dos Santos 《Euphytica》2008,162(3):431-440
The development of successful advanced lines and cultivars in maize is dependent on parental selection and assignment to defined
heterotic groups. So, the objectives of this study were to evaluate genetic variability and identify heterotic groups among
Brazilian popcorn varieties. Thus, diallel crosses of advanced generations of the popcorn hybrids, IAC 112 and Zélia, and
of three open-pollinated popcorn varieties, RS 20, Branco, and SAM were performed. Ten hybrid combinations, the five parents,
and five check treatments were arranged in a block design with four replicates in two tropical-zone locations (CWb climate).
Both additive and non-additive effects were important for grain yield, plant height, ear height, and husk cover. For popping
expansion, only the additive effects were important. Hybrid combinations between the local variety (Branco) and F2 populations (IAC 112 and Zelia) resulted in the third and fourth highest values for popping expansion. The best grain yields
were obtained with hybrid combinations involving SAM. Cultivars Zélia, IAC 112, and RS 20 increased popping expansion, whereas
cultivar Branco increased grain yield of hybrid combinations. The following conclusions may be drawn: Brazilian popcorn populations
have reduced heterosis and genetic variability to popping expansion in relation commercial cultivars; there is genetic variability
among Brazilian popcorn populations that allows the exploitation of additive and non-additive effects for grain yield; it
is possible to increase grain yield by using local varieties; but it would be difficult to obtain commercial hybrids from
local varieties because they have poor performance for popping expansion. 相似文献
5.
Previous studies showed that a T. aestivum-H. villosa disomic substitution line DS4V(4D) showed a high level of resistance to wheat spindle streak mosaic virus (WSSMV). By crossing
DS4V(4D) with the common wheat variety Yangmai #5, plants were obtained that were double monosomic for chromosomes 4V and
4D. Univalents are prone to misdivision at the centromere, and fusion of the derived telocentric chromosomes leads to the
production of Robertsonian whole-arm translocations. We screened the progenies of such double monosomic plants by C-banding
and genomic in situ hybridization and identified one compensating translocation where the short arm of 4V was translocated to the long arm of
4D of wheat, T4VS⋅4DL. RFLP analysis using the group-4 specific probe BCD110 was used to confirm the translocation. The T4VS⋅4DL
translocation stock, accessioned as NAU413, is highly resistant to WSSMV and is also of good agronomic type. The WSSMV resistance
gene located on 4VS was designated Wss1. 相似文献
6.
Summary Genotype-environment interactions in F1 hybrids between a selection of current commereial varicties as male parents and a balanced tertiary trisomic male-sterile female were investigated. Sixteen environments were employed, comprising eight treatments in each of two seasons. Hybrid stabilities in terms of yield response to changing environments, were found to be very similar to those of the parents, however hybrid yields exceeded parental yields in all but one instance. A heterotic effect for plant height was also observed. 相似文献
7.
冬小麦水旱品种间杂交主要性状的遗传分析 总被引：7，自引：0，他引：7
利用水地和旱地两种生态型的品种 ,采用 4× 4不完全双列杂交试验 ,对水旱品种间杂交主要性状的配合力和遗传表现进行了研究。结果表明 ,水地亲本的一般配合力效应对杂种后代主要性状的影响 ,除千粒重外 ,均达到显著或极显著水平 ;旱地亲本的一般配合力效应主要对株高、穗下节长、单株穗数、收获指数等与抗旱性有关的性状影响明显 ,且除株高和收获指数外 ,其余性状P1的方差均大于P2 的方差。说明水地亲本对杂种后代产量性状影响大 ,旱地亲本主要影响抗旱性状 ,水旱两种生态型杂交 ,实现了抗旱与丰产的有机结合。株高、穗下节长、穗粒数、单株产量、单株生物产量和收获指数以加性效应为主 ,而显性基因对单株穗数、千粒重、单穗重的影响较大。旱地小麦产量性状遗传力均较低 ,而株高、穗下节长、收获指数等与抗旱性有关的性状遗传力较高 相似文献
8.
Summary Some photosynthetic characters as-leaf anatomy, leaf photosynthetic rate and CO2 compensation pointdistinguishing C3 and C4 plants and physiological characters as leaf area ratio, nitrogen content, leaf stem ratio and total shoot-to-root and deep root-to-shoot ratios have been studied in rice × sorghum and rice × wheat hybrids. Rice × sorghum 1. has lower values of photosynthetic rate, leaf nitrogen, total root and deep root-to-shoot ratio and CO2 compensation point as of rice parent where as, rice × sorghym 2. is superior in all these characters. Both hybrids lack kranz anatomy. Though both rice × sorghum hybrids show characters of C3 rice plant but rice × sorghum 2. has improved drought tolerance and leaf characters in relation to yield. Rice × wheat hybrid have higher assimilatory area and higher total root-to-shoot ratio. Grains of rice × wheat hybrids are identical to rice grain. However, as grains of rice × wheat hybrid does not contain seed coat, it could be exploited as novel rice germplasm after improvement.Abbreviations T
CO2 compensation point
- T21
CO2 compensation point at 21% O2
- T2
CO2 compensation point at 2% O2
- dR/sR
deep Root-to-shoot Ratio
- LAR
Leaf Area Ratio
- CER
photosynthetic rate
- TR/SR
Total Root-to-Shoot Ratio 相似文献
9.
Summary A leaf rust resistant wheat-rye translocation stock, ST-1, introduced from Japan, comprised distinct morphological types. One type possessed a T1BL·1RS chromosome with genes Lr26, Yr9 and Sr31. A second type carried a new gene, Lr45, located in a large segment of rye chromosome translocated to wheat chromosome 2A. Its structure was identified as T2AS-2RS·2RL. Despite the homoeology of the 2A and 2R chromosomes and the high level of compensation provided by the translocation, Lr45 was not normally inherited and is probably associated with agronomic deficiencies that will prevent its exploitation in agriculture.Contribution No. 94-509-J from the Kansas Agricultural Experiment Station, Kansas State University, Manhattan, USA. 相似文献
10.
Differential gene expression between wheat hybrids and their parental inbreds in seedling leaves 总被引：33，自引：0，他引：33
Differential display of mRNA was used to analyze the differences of gene expression in seedling leaves between heterotic hybrid/nonheterotic
hybrid and their parental inbreds in order to study the molecular basis of heterosis in wheat. The results indicated that
patterns of gene expression in hybrids differ significantly from their parents. Both quantitative and qualitative differences
were observed. The quantitative differences include gene over-expression, gene under-expression in hybrid and dominant expression
of highly-expressed parental genes in hybrids. The qualitative differences include silencing in hybrids of genes expressed
either in male or female parent, and silencing in hybrids of genes expressed in both parents. Expression in hybrid of genes
only expressed either in male or female parent was also observed. It was also found that some genes expressed at high level
in heterotic hybrid were underexpressed or expressed at low level in nonheterotic hybrid. One differentially expressed cDNA
fragment 4B was cloned and sequenced after being confirmed through Northern blot analysis. Homology search in GenBank proved
that the cDNA fragment is a new sequence. The selection of primers for differential RNA display in wheat and the relationship
between wheat heterosis and alteration of gene expression in hybrids as compared to their parental inbreds were also discussed.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
11.
Summary Yield and yield components of F1 hybrids were studied in three experiments at 30×30 cm spacings and in one experiment at 15×15 cm spacings. In the 30×30 cm experiments, 10 of the 41 hybrids tested significantly outyielded their high parents. However, only 2 hybrids significantly outyielded the best cultivar: one hybrid yielded 23 % and the other 16 % more than their respective check cultivars. The four hybrids in the 15×15 cm experiment yielded only 59 to 92% as much as their high parents.In areas where rice is transplanted at relatively wide spacings, the observed levels of F1 heterosis in selected hybrids may be sufficient to warrant production of hybrid rice, if enough hybrid seed can be produced. For direct-seeding at the high rates normal in the USA, the relatively small levels of heterosis and the difficulties of hybrid seed production preclude use of F1 hybrid rice cultivars at present.None of 19 bulk F2 and F3 hybrids in two experiments yielded significantly more than its high parent. Similarly, none of the 12 mixtures included in one experiment yielded significantly more than its high parent. On the basis of yield alone, using bulk F2 or F3 or simple mixture populations is not merited.Contribution from the Western Region, Agricultural Research Service, U.S. Department of Agriculture, and the Department of Agronomy and Range Science, University of California, Davis, California 95616. 相似文献
12.
Summary The polypeptide composition of Fraction-1-Protein (F1P) from rice × sorghum, rice × wheat hybrids and their respective parents have been analyzed by a microelectrofocusing method. The large sub-unit (LSU) is composed of three polypeptides and the small sub-unit (SSU) of two polypeptides in rice and sorghum parents and rice × sorghum hybrids. Similarly, LSU is composed of three polypeptides in the rice and wheat parents and rice × wheat hybrids. Two polypeptides occur in the SSU of rice parent and rice × wheat hybrids where as only one polypeptide in the wheat parent. These polypeptides also differ in their isoelectric points. Based on the previous reports of F1P inheritance in hybrids in other crops, F1P analysis of rice × sorghum and rice × wheat hybrids does not seem to be an important marker to identify such intergeneric hybrids. Since this is first such report of F1P inheritance in hybrids between distantly related plants, its implication in different modes of inheritance are discussed.Abbreviations F1P
Fraction-1-Protein
- IEF
Isoelectric focusing
- pI
Isoelectric points
- LSU
Large sub-unit
- RuBPCase
Ribulose 1,5-Bisphosphate Carboxylase-oxygenase
- SSU
Small sub-unit 相似文献
13.
以与中棉所12及其2个选系为亲本组配的4个杂交棉中棉所28、中棉所29、湘杂棉2号和冀棉18苗期的根和顶端叶为研究材料,采用cDNA-AFLP技术分析苗期杂交棉与亲本的根和叶基因差异表达,并用QuantitativeReal-Time技术加以验证.结果表明:(1)在4个杂交组合中,中棉所12选系是营养生长杂种优势高值亲本;(2)杂交种和亲本间存在显著的基因表达差异,可分为杂交种上调、单亲显性、单亲沉默、杂交种下调4种表达型.4个杂交组合在三叶期根和叶中差异表达基因的4种类型比例趋势基本一致,单亲差异表达型(包括显性和沉默表达)在根和叶中所占比例较高,杂种下调表达型所占比例较低,反映出苗期单亲差异表达型在杂种优势形成中起主要作用;叶部差异表达基因数目和比例(29.20%～46.09%)比根(15.65%～22.49%)高的多,说明叶中基因差异表达可能比根中基因差异表达对杂种优势形成作用更大;(3)高值亲本中棉所12选系与杂交棉共同表达的基因多于低值亲本与杂交棉共同表达的基因,从分子水平上证明中棉所12选系在杂交棉冀棉18、中棉所29和中棉所28的苗期营养生长杂种优势产生中起优势亲本的作用;(4)4种杂交组合差异表达基因(包含叶和根)占总表达基因的27.00%～34.56%,分析差异表达基因类型和4个杂交组合的关系发现,超显性效应占3.30%～7.17%,超低亲效应占2.62%～4.14%,低亲效应占5.65%～13.03%,显性效应和加性效应是主要的杂种优势效应,占79.52%～83.79%.多种杂种优势效应的并存说明杂种优势可能是多基因共同作用产生多种效应的结果;(5)超亲优势组合中棉所28的超显性效应占7.17%,明显高于其他3个表现中亲优势组合,说明杂交种上调表达型可能对苗期杂种优势产生起重要作用. 相似文献
14.
The phenomenon of mutant heterosis was studied in barley using F1 hybrids developed from crosses involving two mutants derived from the same parent variety (067AR× 032AR), or from crosses of mutants with their parent varieties (Diva × 228DV; 437MG × Mg 4170). The agronomic performance (plant height, tillers per plant, kernel number and weight per plant) of F1 hybrids was evaluated in relation to the corresponding parent variety used for mutant development. Wide-space sowing (0.O6 m2/plant) was applied to allow the full expression of hybrid vigour. The hybrids significantly exceeded their parent varieties in various yield parameters in each year of the experiment, Depending on the cross, the level of heterosis ranged from 39.45% to 82.1% for kernel number and from 44.45% to 91.2% for kernel weight, as an average of observations over three years. The increased yield of hybrids was accompanied by an increase in spikes/plant, without significant changes, in most cases, in yield components such as kernels/spike and 1000 kernel weight. The height of F1 plants remained similar to the corresponding parent variety. Doubled haploicls (DH) were developed through anther culture from three F1 hybrids to determine whether the heterotic effect could be fixed, even partly, in homozygous lines. Twenty-eight, 42 and 68 DH lines per cross were produced, and evaluated in the field, space-planted at 0.06 m2/plant, together with hybrids and parent varieties. The best-performing DH lines were evaluated again the following season in a conventional field trial. We were able to select 1.5 -14.3% of‘F1,-performing’DH lines per hetorotic cross combination, which, in two years of studies, reached the yield of heterotic hybrids and significantly out-yielded the parent variety in plot. The yield potential of DH lines was better expressed under a wide sowing density, but even under normal growing conditions, the yield of the best selected DH lines surpassed their corresponding parent varieties by 17.77ndash;30.1%. 相似文献
15.
Zu-Jun Yang Guang-Rong Li Ju-Qing Jia Xue Zeng Meng-Ping Lei Zi-Xian Zeng Tao Zhang Zheng-Long Ren 《Euphytica》2009,167(2):197-202
Two amphiploids, AF-1(Triticum aestivum L. cv. Anyuepaideng–Secale africanum Stapf.) and BF-1 (T. turgidum ssp. carthlicum–S. africanum), were evaluated by chromosomal banding and in situ hybridization. The individual S. africanum chromosomes were identified in the BF-1 background by sequential C-banding and genomic in situ hybridization (GISH), and
were distinguishable from those of S. cereale, because they exhibited less terminal heterochromatin. Fluorescence in situ hybridization (FISH) using the tandem repeat
pSc250 as a probe indicated that only 6Ra of S. africanum contained a significant hybrid signal, whereas S. cereale displayed strong hybridization at the telomeres or subtelomeres in all seven pairs of chromosomes. Extensive wheat–S. africanum non-Robertsonian translocations were observed in both AF-1 and BF-1 plants, suggesting a frequent occurrence of chromosomal
recombination between wheat and S. africanum. Moreover, introgression lines selected from the progeny of wheat/AF-1 crosses were resistant when field tested with widely
virulent strains of Puccinia striiformis f. sp. tritici. Three highly resistant lines were selected. GISH and C-banding revealed that resistant line L9-15 carried a pair of 1BL.1RS
translocated chromosomes. This new type of S. africanum derived wheat–Secale translocation line with resistance to Yr9-virulent strains will broaden the genetic diversity of 1BL.1RS for wheat breeding. 相似文献
16.
Summary Hybrids between T. ambiguum and T. repens were successfully established after ovule culture. The hybrids were male sterile but one of the hybrids produced a single seed when backcrossed to T. repens, while the other produced a significantly greater number of seeds. The majority of the backcross hybrids from the latter had 48 chromosomes, being produced from the fertilisation of unreduced gametes of the F1 hybrid by T. repens pollen. Regular meiosis in the BC1 hybrid resulted in the production of balanced gametes containing the full complement of T. repens chromosomes and the polyhaploid set of T. ambiguum chromosomes. There was no difficulty in establishing a substantial population of BC2 hybrids. The meiotic behaviour of the BC1 hybrid indicated that it should be possible to transfer genes from T. ambiguum into white clover T. repens. The significance of the results in terms of the use of alien variation in the improvement of white clover is discussed. 相似文献
17.
Summary F1 hybrids of triazine resistant Brassica napus and triazine susceptible B. oleracea were morphologically intermediate to the parent species. Of 49 hybrids examined, 44 had 28 chromosomes, two had 37, one had 38 and two had 56. The 38-chromosome plant was thought to be a matromorph, the others, A1C1C (28), A1C1CC (37) or A1A1C1C1CC (56) type hybrids. Pollen stainability averaged 9.0% in the sesquidiploid, 32.0% in the tetraploids and 89.5% in the hexaploids. All the interspecific hybrids were resistant to 1.0×10-4 mol L-1 atrazine. The sesquidiploid hybrids produced gametes with chromosome numbers ranging from 9 to 17 and the tetraploid hybrid gametes had chromosome numbers from 15 to 22. Most hybrids produced self-seed. The partial fertility of these hybrids may permit their backcrossing to one or both parents. 相似文献
18.
19.
基于寡核苷酸探针套painting的染色体鉴定技术简单、经济和高效, 可以促进小麦品种及亲缘物种染色体识别和变异体鉴定, 提高染色体工程效率。我们前期开发了寡核苷酸探针套, 包含pAs1-1、pAs1-3、AFA-4、(GAA)10和pSc119.2-1共5个探针。本研究通过一次荧光原位杂交(FISH), 对源于17个非整倍体的18份材料分析发现, 其中14个染色体组成正确, 可以清晰识别相应的缺体、四体和端体。还构建了基于寡核苷酸探针套涂染的、能准确识别3个基因组和7个部分同源群染色体的高清核型, 发现4个非整倍体发生变异, 其中从N5BT5D中鉴定出一个可能的小片段相互易位系T6AS·6AL-6DL和T6DS·6DL-6AL。进一步对7个地方品种、10个栽培品种(系)和1个人工合成小麦分析, 发现15条染色体存在多态性, 涉及6条B组(除4B)、5条A组(除1A和3A)和4条D组(1D、2D、4D和7D)染色体, 可以清晰识别我国小麦生产上广泛应用的3种易位类型(T1RS·1BL、T6VS·6AL及相互易位T1RS·7DL和T7DS·1BL), 省去了基因组原位杂交(GISH)程序。另外, 对5个亲缘物种分析发现, 该探针套可以识别栽培一粒小麦、硬粒小麦Langdon、荆州黑麦、长穗偃麦草(2n=2x=14)全部和中间偃麦草30条染色体, 并构建了这5个物种的核型。本研究结果证实该寡核苷酸探针套可以有效用于小麦及亲缘物种染色体鉴定, 高清晰的中国春非整倍体核型为小麦染色体工程提供了参考标准。 相似文献
20.
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