首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 562 毫秒
1.
The agricultural use of water is higher than 85% in the western USA, resulting in an increasing water deficit in the region; this situation is commonly encountered throughout the world where irrigated and irrigation-assisted production systems are operational. The objective of this study was to examine differences among dry bean (Phaseolus vulgaris L.) landraces and cultivars in terms of water use efficiency (WUE), subsequently identifying those with a high water use efficiency. Six medium-seeded (25–40 g 100 seed wt−1) landraces and cultivars of pinto and red market classes were evaluated in intermittent drought-stressed (DS) and non-stressed (NS) environments at Kimberly, Idaho, USA in 2003 and 2004. Each market class comprised one each of a landrace and old and new cultivars. Mean evapotranspiration (ET) in the NS environment was 384 mm in 2003 and 432 mm in 2004; the respective ET values in the DS environment were 309 and 268 mm. Mean seed yield was higher in the DS (2678 kg ha−1) and NS (3779 kg ha−1) environments in 2004 than in 2003 (688 and 1800 kg ha−1, respectively). Under severe drought stress in 2003, WUE in the pinto bean ranged from 1.5 for the Common Pinto landrace to 4.4 kg ha−1 mm−1 water for cv. Othello. The Common Red Mexican landrace had the highest WUE (3.7), followed by cvs. NW 63 (2.8) and UI 259 (1.4) in the red market class. Under favorable milder climatic conditions in 2004, the mean WUE value was 10 kg ha−1 mm−1 water in the DS environment and 8.7 kg ha−1 mm−1 water in the NS environment. We conclude that dry bean landraces and cultivars with high WUE should be used to reduce dependence on irrigation water and to develop drought-resistant cultivars to maximize yield and WUE.  相似文献   

2.
Grapefruit growers in the tropics require information about existing and new citrus cultivars with high productivity potential. The objective of this study was to determine the growth, yield, and fruit quality performance of seven pigmented and four white grapefruit cultivars under the dry tropic conditions of Colima, Mexico. The trees were budded on sour orange (Citrus aurantium L.) rootstock and planted at a distance of 8 × 4 m. ‘Oroblanco’ and ‘Marsh Gardner’ white-fleshed grapefruit cultivars and ‘Chandler’, a pink-fleshed pummelo, were the largest trees with the greatest height (5.0–5.6 m), canopy diameter (6.2–6.3 m), trunk diameter (21.9–23.3 cm), and canopy volume (109–123 m3). Lower height (4.3–4.8 m) and canopy volume (73–96 m3), but with similar canopy diameter to the previously mentioned cultivars, were recorded for the remaining pigmented cultivars. ‘Chandler’ pummelo and four pigmented grapefruit cultivars (‘Shambar’, ‘Río Red’, ‘Ray Ruby’, and ‘Redblush #3’) had yearly productions of 34.8, 34.9, 34.1, 32.7, and 30.6 ton ha−1, respectively. The most productive white grapefruit cultivar was ‘Marsh Gardner’ (30.5 ton ha−1). Grapefruit cultivars having the largest fruit size showed a higher inverse relationship between fruit weight and yield than those with small fruit. Most genotypes had higher values of fruit weight, juice content, and maturity index than those required by the local market. The most promising grapefruit cultivars based on their acceptable growth, yield superior to 30 ton ha−1, and acceptable fruit color were ‘Río Red’, ‘Shambar’, ‘Ray Ruby’, and ‘Redblush #3’.  相似文献   

3.
The effect of two major dwarfing (Rht-B1b and Rht-D1b) genes varies with environment. Near-isogenic pairs (i.e., tall and semidwarf) of six spring wheat lines, included in the International Adaptation Trial (IAT), were grown in 81 trials around the world from 2001 to 2004. Trial yields ranged from 1 to 8 t ha−1 with a mean of ca. 4 t ha−1. Overall, the yield advantage of the lines possessing the dwarfing gene was ca. 10% and was particularly evident in trials where the mean height of semidwarf isolines exceeded ca. 80 cm. However, the yield advantage was greater in the slightly taller and older lines (Pavon and Galvez) than in the newer lines Nesser and Kauz and the two durum lines. Sixteen pairs of semidwarf/tall near-isolines were grown in six managed drought environment trials at CIMMYT in northwestern Mexico. In these trials, height and yield differences were small and/or negligible in the most droughted environment (2.5 t ha−1) and the slope of yield versus height for each isoline pair became consistently negative with increase in irrigation. In the IAT, the slope of the yield versus height was much more variable at low heights or yields, presumably due to the fact that there were many more factors driving the response. Even at the point where the slope became consistently negative (ca. between 2 and 4 t ha−1), there were some trials where tall isolines equaled or exceeded the yield of semidwarf isolines, particularly in the most recent developed cultivar, Kauz. For submission to Euphytica as part of special issue “Challenges to International Wheat Breeding”. From the International Symposium on Wheat Yield Potential: Challenges to International Wheat Breeding, Days Inn, Ciudad Obregón, Sonora, Mexico, March 19–24th, 2006.  相似文献   

4.
This study was carried out to verify the applicability of variable rate fertilization (VRF) based on soil testing and diagnosis of rice plant growth for high quality rice production of var. Chucheongbyeo at the farm level. The field trials were conducted at Icheon in Gyeonggi province on a 10 ha farm consisting of 45 experimental fields. For comparative study, 15 field trials were carried out adopting fertilizer management (FPM) practices currently used by farmers. FPM fields were managed by each rice grower using current cultivation methods, but in each VRF field fertilizer application was prescribed using soil test results and the amount of N fertilizer for top-dressing at panicle initiation stage was calculated using rice growth value at that stage. In VRF fields, the total amount of N fertilizer application was less (72 kg ha−1) than that in FPM fields (103 kg ha−1). However, the amount of K2O fertilizer application was more in VRF fields (60 kg ha−1) than that in FPM fields (52 kg ha−1). The amount of P2O5 fertilizer application was similar between the VRF and FPM fields. Plant height was significantly shorter and the number of tillers was significantly more at VRF fields than at the FPM fields. Coefficient of variation (CV) of each growth characteristic measured in VRF was lower than that of FPM fields at panicle initiation stage. There was no difference in culm and panicle length and panicle number between them at the grain filling stage, but CV of panicle numbers per m2 decreased in VRF compared with that of the FPM fields. Rice yield was not different between VRF and FPM fields despite higher brown rice recovery and 1,000-grain weight in VRF fields. Under VRF management, head rice yield increased due to an increase in head rice ratio accompanied by a reduction in brown rice protein content and variation of quality characteristics. These results suggest that VRF application based on soil tests and measurement of rice growth value at panicle initiation stage has the potential for quality control and production of high quality rice through increasing uniformity of growth and reducing the variability in quality among individual fields.  相似文献   

5.
Summary The increasing popularity of organic agriculture and health food products has led to a renewed interest in hulled wheat species such as emmer (Triticum turgidum ssp. dicoccumSchubler). Knowledge on agronomic and quality traits is required for effective and efficient use of germplasm collections in breeding programs. The objective of this study was to estimate agronomic and grain quality traits of emmer wheat cultivated in Italy. A total of 20 emmer accessions consisting of landraces, breeding lines or cultivars selected from landraces and modern cultivars were examined under low input conditions. The study was conducted for three successive years (2002–2004) at one location of Southern Italy (Foggia). The entries were characterized for agronomic and qualitative traits [grain yield (t ha−1), thousand grain weight (g), test weight (kg hl−1), grain protein content (%), HMWG composition, dry gluten content (%), gluten index and yellow index, alveograph indices and Total Organic Matter (TOM) on cooked pasta]. The results showed a large genetic variability for most of the traits measured and, even if most of the accessions showed inferior bread- and pasta-making performance, modern cultivars exhibited improved quality traits with some potential to perform healthy and tasty food.  相似文献   

6.
The pea crop (Pisum sativum L.) is a convenient source of plant protein for animal feeding. The objective of this research was to evaluate field pea breeding lines for agronomic performance and seed quality focussed to their use in a sustainable production. Thirty-five field pea breeding lines and six elite cultivars were evaluated for their agronomic value in field in Spain upon 20 traits related to flower, cycle, plant architecture, productivity and seed quality. The lines showed significant differences in all the quantitative traits evaluated and three of them, namely MB-0307, MB-0308, and MB-0319 were chosen to be evaluated, together with the advanced cultivar ZP-1233, in field and in growing chamber for agronomic performance, seed quality and ability for sustainable production. The four accessions displayed high seed protein content that had significant effect of cropping density with averages of 253.6 g kg−1 under low cropping density of 60 plants m−2 and 259.1 g kg−1 under high cropping density of 90 plants m−2, therefore, the low cropping density should be regarded as the most convenient. Average yield of the lines MB-0307, MB-0308 and MB-0319 and the cultivar ZP-1233 was fair (197.5 g m−2), probably due to the absence of fertilizers and irrigation, aiming for the sustainability of the crop. Intercropping with rye and herbicide application resulted in no differences on the seed yield; therefore, the ability of the breeding lines to grow without herbicide seems to be demonstrated, while the germination of the seeds at low temperature was very good. These results indicate that field pea could be a new protein crop in the North of Spain to satisfy the demand of plant protein for animal feed, based upon adapted breeding lines that combine the ability for growing under sustainable conditions with other desirable agronomic traits maintaining an adequate productivity.  相似文献   

7.
Use of DNA-based markers can accelerate cultivar development in variable cultivation environments since, in contrast to phenotype, DNA markers are environment-independent. In an effort to elucidate the genetic basis of genotype-by-environment interaction (G × E) for yield of rice (Oryza sativa L.), the associations between 139 AFLP markers and grain yield were determined for rice grown in fresh water (EC of 0.65 dS m−1) and saline conditions (EC of 4–8 dS m−1) with 0 kg ha−1 or 100 kg ha−1 nitrogen fertilizer in the years 2000 and 2001. A population of recombinant inbred lines of rice, developed from an IR29 × Pokkali cross, was used in the study. Both genotype × salinity and genotype × nitrogen level interactions were significant, with the genotype × salinity interaction being stronger. Through multiple regression analysis using a stepwise procedure for selecting markers, 36 markers were detected for grain yield in the four test conditions and of these 28 were detected in only one test condition implying strong environmental specificity for yield QTL expression. However, the fact that eight QTLs were detected in more than one test condition points to the existence of wide-adaptability genes in this cross. Markers with significant associations with yield explained between 37% and 48% of the yield variation in each test condition. Superior genotypes of rice were identified in all four test conditions based on their marker signatures. Furthermore, across N fertilizer regimes, yield predicted from summed additive effects of QTLs were significantly correlated with observed yield in the same year and across years. Thus marker-assisted selection can help breeders overcome the problem of low selection efficiency encountered during phenotypic selection for yield in stress environments.  相似文献   

8.
Summary During the last decades extensive progress has been achieved in winter barley breeding with respect to both, yield and resistance to fungal and viral diseases. This progress is mainly due to the efficient use of the genetic diversity present within high yielding adapted cultivars and – with respect to resistance – to the extensive evaluation of genetic resources followed by genetic analyses and introgression of respective genes by sexual recombination. Detailed knowledge on genetic diversity present on the molecular level regarding specific traits as well as on the whole genome level may enhance barley breeding today by facilitating efficient selection of parental lines and marker assisted selection procedures. In the present paper the state of the art with respect to virus diseases, i.e. Barley mild mosaic virus, Barley yellow mosaic virus, and Barley yellow dwarf virus is briefly reviewed and first results on a project aiming on a genome wide estimation of genetic diversity which in combination with data on yield and additional agronomic traits may facilitate the detection of marker trait associations and a more efficient selection of parental genotypes are presented. By field tests of 49 two-rowed and 64 six-rowed winter barley cultivars the genetic gain in yield for the period 1970–2003 was estimated at 54.6 kg ha−1 year−1 (r2 = 0.567) for the six-rowed cultivars and at 37.5 kg ha−1 year−1 (r2 = 0.621) for the two-rowed cultivars. Analysis of 30 SSRs revealed a non-homogenous allele distribution between two and six-rowed cultivars and changes of allele frequencies in relation to the time of release. By PCoA a separation between two and six-rowed cultivars was observed but no clear cut differentiation in relation to the time of release. In the two-rowed cultivars an increase in genetic diversity (DI) from older to newly released cultivars was detected.  相似文献   

9.
Maize (Zea mays L.) is grown on 15 million ha in eastern and southern Africa. Several diseases are of common occurrence in the region and regularly result in significant yield losses. A collaborative regional disease nursery (REGNUR) project was initiated in 1998 to identify and increase access to disease resistant germplasm, generate and disseminate information on disease and insect resistance sources, and facilitate the development of resistant cultivars by project partners. A diallel among 12 elite inbred lines was formed with the specific objective of evaluating the combining ability of these inbred lines for grain yield and resistance to seven diseases. The trial was grown at six sites in 2001. Results showed that both general (GCA) and specific combining ability effects were significant for most diseases. On the average, GCA accounted for 69% of resistance to diseases and only 37% of variation for grain yield. Correlations between GCA effects for disease scores were generally non-significant, implying that it is possible to pyramid genes for disease resistance in inbred lines. This underscores the need for screening for resistance to prevailing diseases using artificial inoculation or reliable hot-spots. Based on GCA effects for grain yield and across diseases, P12 and P6 were the best inbred lines. The crosses P4 × P9 (6.7 t ha−1) and P4 × P12 (6.9 t ha−1) were the best hybrids in the earlier maturity group, while P3 × P9 (8.3 t ha−1) and P2 × P8 (7.4 t ha−1) were the best hybrids in the late maturity group.  相似文献   

10.
Ideotype design for lodging-resistant wheat   总被引：2，自引：0，他引：2  
The plant characteristics required to make wheat lodging-proof for the least investment of biomass are calculated using a validated model of the lodging process and information about the dry matter costs of altering lodging-associated characters. The plant characteristics required to give a crop yielding 8 t ha−1 with 500 shoots m−2 and 200 plants m−2, a lodging return period of 25 years include a height of 0.7 m, a root plate spread of 57 mm, and for the bottom internode a wall width of 0.65 mm with a diameter/material strength combination ranging from a diameter of 5.86 mm with a material strength of 20 MPa to a diameter of 4.00 mm with a material strength of 50 MPa. It is estimated that this ideotype would require 7.9 t ha−1 of stem biomass and would have a harvest index of 0.42. Observations of a wide range of varieties grown using crop management to maximise lodging resistance without reducing yield potential showed that the root plate of the best variety was 7 mm less than the ideotype target, the stem character targets were achieved but not all in one variety, and the height target was achievable with the use of plant growth regulators. Plant breeders must therefore focus on selecting for a wider root plate and combining the appropriate stem strength characteristics.  相似文献   

11.
Common bean (Phaseolus vulgaris L.) is the most important legume crop in Kenya. It is cultivated across a wide range of agro-ecologies which include high potential and marginal areas. Eastern Kenya alone, largely semi-arid, accounts for 35% of the country’s total bean production. Bean farmers mainly small-scale have limited access to quality seed, chemical pesticides and fertilizer. Therefore, bean yield under on-farm conditions still remains below 500 kg ha−1 while the potential is about 1,200 kg ha−1 under semi-arid conditions. To asses the farmers’ views on bean varieties and a key insect pest and associated constraints contributing to yield loss, research was undertaken. The research included survey to quantify the yield loss and Participatory Rural Appraisal to determine the level of adoption and criteria for variety choice in semi-arid eastern Kenya (SAEK). The results show that farmers consider drought and insect pest problems as main causes for low yields. The adoption rate for improved varieties is high but self sufficiency in beans stands at 23% in the dry transitional (DT) agro-ecology and at 18% in the dry mid-altitude (DM) agro-ecology, respectively. This could be attributed to low adaptability since most of the improved varieties grown were selected for high potential areas but now found in marginal areas. Drought, earliness, yield stability, and insect pest resistance are the main reasons for choice of varieties by farmers. Bean fly (Ophiomyia sp.) was identified as one of the key crop pests of beans limiting yield. Besides, African bollworm (Helicoverpa armigera) and bean aphid (Aphis fabae) were ranked higher. Due to limitations of the conventional breeding approach, a participatory plant breeding approach is suggested so as to provide an opportunity to develop insect pest resistant varieties adapted to the SAEK region.  相似文献   

12.
This research reports responses to selection and changes in general (GCA) and specific (SCA) combining abilities after three cycles of a modified reciprocal recurrent selection procedure (MRRS) in EPB-4 and EPB-5 maize populations. In the MRRS procedure a cycle can be completed in 1 or 2 years depending on the availability of winter breeding nurseries. The original and the three selection cycles of the two populations per se (eight entries) and the partial diallel developed from the crosses between them (16 entries) were evaluated in six environments. Realized response to selection on the population cross was 7.25% cycle−1 for grain yield, −13.63% cycle−1 for plant lodging, and 11.93% cyle−1 for prolificacy, whereas plant and ear heights remained unchanged. GCA estimates increased with selection cycles for both populations for grain yield and prolificacy, and decreased for plant lodging, indicating that the frequency of favorable alleles with additive effects for these traits increased with the MRRS cycles in both populations. SCA estimates increased for grain yield and prolificacy indicating that the frequency of favorable complementary alleles at loci with non-additive effects in the reciprocal populations increased with the MRRS cycles. For grain yield, SCA effects increased more than GCA effects with selection cycles, indicating that MRRS exploited more the non-additive effects than the additive effects for the improvement of this trait. The overall results showed that the MRRS procedure was highly effective in improving the population cross, exploiting both GCA and SCA effects.  相似文献   

13.
With the objective of selecting superior recombinant lines of snap bean, four segregating F2 populations were selected by early generation testing and advanced by single seed descent. In a randomized complete block design with two replications within sets 120 F6:7 lines were obtained and evaluated for seven traits of agronomic interest. The mean pod yield of the F6:7 generation was 72% higher than in generation F2, confirming the efficiency of early selection. There was genetic variability in the F6:7 lines within the sets. The selection of superior genotypes was possible by the high estimates of narrow-sense heritability. Highest gains in simultaneous selection of traits were expressed by the indices proposed by Mulamba & Mock for the genetic standard deviation and by Williams, based on tentatively attributed arbitrary weights. Line 3 of the F6:7 generation, with a yield of 8,050.0000 kg ha−1 and pod fiber content of 0.3650% is highly promising to be release as new cultivar.  相似文献   

14.
氮肥用量及钾肥施用对稻麦周年产量及效益的影响   总被引：9，自引：0，他引：9  
为探明优化施氮量与高施氮量下不同钾肥施用处理对稻麦周年产量及效益的影响。本试验于2010年5月–2011年7月在江苏省如皋市农业科学研究所试验基地的田间稻麦轮作条件下,对常规粳稻品种镇稻11和春性中筋品种扬麦16设置了两个氮肥用量下不同钾肥用量及施用方法处理,测定稻麦周年的产量和组成因子,成熟期不同器官的氮、钾浓度和累积量,氮、钾利用效率及经济效益。试验结果表明,钾肥的施用显著提高了周年稻麦的产量,同时提高了稻麦的有效穗数、穗粒数和结实率,钾肥的利用效率和经济效益。稻麦周年钾肥(K2O)的偏生产力(PFP)、农学效率(AE)、回收利用率(RE)和经济效益均以周年钾肥(K2O)土壤施用150 kg hm-2 + 叶面喷施16.2 kg hm-2 (KS150 + KF16.2)处理最高。氮肥用量的结果表明,相对于优化施氮量,高施氮量有利于提高水稻的氮素营养而增产,但对稻麦周年产量的影响不显著,且优化施氮量的氮肥利用效率及经济效益均高于高施氮量。因此,综合考虑土壤环境因素、经济效益和肥料资源管理,本地区最佳氮肥(N)用量为水稻200 kg hm-2,小麦180 kg hm-2;最佳钾肥(K2O)用量及方法为水稻土壤施用90 kg hm-2 + 叶面喷施9.7 kg hm-2 (KS90 + KF9.7),小麦土壤施用60 kg hm-2 + 叶面喷施6.5 kg hm-2 (KS60 + KF6.5)。  相似文献   

15.
Nitrogen (N) and plant density are two crucial factors that affect winter wheat (Triticum aestivum L.) yield and quality, but little is known regarding the effects of interactions between these two factors on the amount and size distribution of protein fractions and quality traits. We grew the bread wheat cultivar Jinan17 in two successive seasons (2012–2013 and 2013–2014) at three densities of 120 plants m−2 (low), 180 plants m−2 [the usual rate for a multiple-spike cultivar with high tillering ability in the North China Plain (NCP)], and 240 plants m−2 (high) and two levels of N fertilisation of 0 (low N availability treatment without N fertilisation) and 240 kg ha−1 (the usual N rate for winter wheat production in the NCP) to evaluate the effect of N level × plant density interaction on grain yield, grain protein concentration, the amount and composition of protein fractions, dough development time, dough stability time, and loaf volume. The effect of plant density on Jinan 17 grain yield and quality differed between the two N levels. As plant density increased, all the parameters listed above decreased under 0 kg ha−1 N fertilisation, but increased under 240 kg ha−1 N fertilisation. Stepwise regression analysis showed that the dough rheological properties and breadmaking quality of Jinan 17 were affected by plant density under both N levels, primarily through changes in the polymerisation degree of glutenins in the flour.  相似文献   

16.
以重穗型冬小麦品种兰考矮早八为材料,研究了正常播期(10月10至12日)和适度晚播(10月24至26日)条件下,高(300万株 hm-2)、中(225万株 hm-2)、低(150万株 hm-2)密度对其干物质和氮素积累转运及籽粒产量和品质的影响。结果表明,不同播期条件下,各密度处理开花期和成熟期单茎干物质和氮素积累量均随播种密度降低而增加,适当晚播和中、低密度有利于单茎干物质和氮素积累,尤其是穗部积累量的提高。正常播期和低密度以及晚播和中等密度处理开花前营养器官贮藏干物质向籽粒的转运量和花前贮藏物质对籽粒重的贡献率显著高于其他处理。正常播期和中、低密度处理以及晚播和中、高密度处理显著提高籽粒淀粉和蛋白质的含量与产量以及籽粒产量,使小麦籽粒产量和品质同步提高。在本试验条件下,兰考矮早八兼顾高产和优质的正常播期和晚播的适宜播种密度分别为150~225万株 hm-2和225~300万株 hm-2。  相似文献   

17.
Genetic variability, correlation, path coefficient analysis and test of normality was conducted in an F8 recombinant inbred aerobic rice population developed by single seed descent method to evaluate its potential as a mapping population. Estimates of genotypic variance, phenotypic variance, genotypic coefficient of variance (GCV), phenotypic coefficient of variance (PCV), heritability in the broad sense (H) and expected genetic advance at 5% selection index (GA) for grain yield and other attributing characters were computed. In all the cases, PCV was higher than GCV indicating the influence of environment on the characters. High heritability coupled with high GA was observed for several plant traits; number of tillers, plant height, total number of spikelets panicle−1, biomass plant−1, straw weight, harvest index and grain yield plant−1 and hence offered good scope for selection. Grain yield plant−1 was found to be positively correlated with plant height, number of tillers, panicle length, panicle exsertion, number of panicles plant−1, single panicle weight, test weight, number of fertile spikelets panicle−1, straw weight, biomass plant−1, harvest index and grain breadth both at genotypic and phenotypic levels. Harvest index exerted maximum positive direct effect, followed by biomass plant−1 and straw weight on grain yield plant−1 at phenotypic level. Shapiro-Wilks “W test of normality” indicated that the population was skewed towards female parent IR50 for some traits and for some others towards Moroberekan, the male parent. Most of the characters that showed skewness were platykurtic with a kurtosis value of less than 3.  相似文献   

18.
Cytoplasmic-nuclear male-sterility is an important biological tool, which has been used by plant breeders to increase yields in cross-pollinated cereals and vegetables by commercial exploitation of the phenomenon of hybrid vigor. In legumes, no such example exists due to the absence of an economic way of mass pollen transfer from male to female parent. Pigeonpea [Cajanus cajan (L.) Millsp.], however, is a different legume where a moderate level of insect-aided natural out-crossing (25–70%) exists and it can be used to produce commercial hybrid cultivars, if an efficient and stable cytoplasmic-nuclear male-sterility (CMS) system is available. This paper reports the development of a stable CMS system (ICP 2039A), derived from an inter-specific hybrid of Cajanus cajanifolius, a wild relative of pigeonpea, with a cultivar ICP 11501. Using this genetic material, designated as the A4 cytoplasm, a number of fertility restorers and maintainers have been developed. The best short-duration experimental pigeonpea hybrid ICPH 2470 produced 3205 kg ha−1 grain yield in 125 days, exhibiting 77.5% advantage over the control cultivar UPAS 120. At present, all the important biological systems necessary for a successful commercial hybrid breeding program are available in pigeonpea and the package of this technology has been adopted by private seed sector in India for the production and marketing of hybrid varieties.  相似文献   

19.
Recombinant inbred line (RIL) populations of rice are useful genetic sources for map-based cloning of agronomically important genes. Zhe733 is a high-yielding indica cultivar from China conferring resistance to rice blast (RB), rice water weevil (RWW) and straighthead; whereas Kaybonnet low-phytic acid 1-1 (KBNTlpa) is a mutant of a tropical japonica cultivar from the US containing low-phytic acid with average yield, and is susceptible to some RB races, RWW, and straighthead. A 355 RIL F10−11 population derived from the cross of KBNTlpa × Zhe733 was recently released. Simple sequence repeat (SSR) markers were used to evaluate 269 RILs of this population. A total of 107 polymorphic markers were mapped on all rice chromosomes representing a total of 1,016.3 cM of genetic distance. Two hundred and thirty-five KBNTlpa × Zhe733 RILs (KZRILs) were clustered into seven groups based on allele frequencies of SSR markers. Twenty-three markers (21.1%) on chromosomes 3, 6, 7, 9, and 11 were found to favor Zhe733 (χ 2 = 16.8−189.7 and P < 0.01) and five markers (4.6%) on chromosome 1 and 6 were found to favor KBNTlpa (χ 2 = 18.5−46.6 and P < 0.01). Marker segregations were observed to be normal for both parents except 26 (10.2%) KZRILs were found to skew toward Zhe733 (χ 2 > 15.7 and P < 0.01). Furthermore, the average frequencies of heterozygosity and non-parental alleles per KZRIL were 1.3% (0.0−38.9%) and 0.4% (0.0−15.0%), respectively. Thirteen heterozygous KZRILs were found at more than five markers loci and nine KZRILs were found with more than five non-parental alleles representing 5.1 and 3.5% of 255 KZRILs. Overall, this KZRIL population is a good population with relatively low frequencies of heterozygosity and non-parental alleles, and with relatively low percentages of skewed markers and skewed KZRILs. The profiles of these SSR markers should facilitate molecular tagging critical genes controlling yield, RB, RWW, and straighthead resistance.  相似文献   

20.
Investigations on concentration of mineral elements including Fe and Zn in wheat grains are important for human health. Two hundreds and sixty-five cultivars and advanced lines were collected and sown at Anyang experimental station of the Institute of Crop Science of the Chinese Academy of Agriculture Sciences in season 2005–2006 to evaluate the genetic variation of major mineral element concentrations in wheat grain. Twenty-four selected cultivars were also planted at seven representative locations in seasons 2005–2006 and 2006–2007 to evaluate the effects of genotype, environment, and genotype by environment interaction on mineral element concentrations. The 265 genotypes displayed a large variation for all mineral elements investigated including Fe and Zn, ranging from 28.0 to 65.4 mg kg−1 and 21.4 to 58.2 mg kg−1 for Fe and Zn, with mean values of 39.2 and 32.3 mg kg−1, respectively. Jimai 26, Henong 326, and Jingdong 8 displayed high Fe and Zn concentrations, and Jimai 26 and Henong 326 also displayed high concentrations of Cu, Mg, K, P, and protein content. Jingdong 8 is the most promising leading cultivar for increasing Fe and Zn concentrations. All mineral element concentrations including Fe and Zn were largely influenced by environment effects. Production of high Fe concentration can be best secured at Jiaozuo and Jinan, and high Zn concentration can be best secured at Jinan and Xuzhou, since samples from these locations in the two seasons are characterized by high Fe or Zn concentration, compared with the other locations. High and significant genotype by environment interaction effects on all mineral element concentrations were also observed, with ratios of genotype by environment to genotype variances all larger than 1.20. Grain Fe concentration was highly significant and positively correlated with that of Zn, indicating a high possibility to combine high Fe and Zn traits in wheat breeding. It also indicated strong positive correlations between concentrations of Fe, Zn, and protein content.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号