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1.
Pearl millet [Pennisetum glaucum (L.) R. Br.] is a major warm-season cereal, grown primarily for grain production in the arid and semi-arid tropical regions of Asia and Africa. Iron (Fe) and zinc (Zn) deficiencies have been reported to be a food-related primary health problem affecting nearly two billion people worldwide. Improving Fe and Zn densities of staple crops by breeding offers a cost-effective and sustainable solution to reducing micronutrient malnutrition in resource poor communities. An understanding of the genetics of these micronutrients can help to accelerate the breeding process, but little is known about the genetics and heterosis pattern of Fe and Zn densities in pearl millet. In the present study, ten inbred lines and their full diallel crosses were used to study the nature of gene action and heterosis for these micronutrients. The general combining ability (GCA) effects of parents and specific combining ability (SCA) effects of hybrids showed significant differences for both of the micronutrients. However, the predictability ratio (2σ2gca/(2σ2gca + σ2sca)) was around unity both for Fe and Zn densities, implying preponderance of additive gene action. Further, highly significant positive correlation between mid-parent values and hybrid performance, and no correlation between mid-parent values and mid-parent heterosis confirmed again the predominant role of additive gene action for these micronutrients. Barring a few exceptions with one parent, hybrids did not outperform the parents having high Fe and Zn levels. This showed that there would be little opportunity, if any, to exploit heterosis for these mineral micronutrients in pearl millet. In general, high Fe and Zn levels in both of the parental lines would be required to increase the probability of breeding high Fe and Zn hybrids.  相似文献   

2.
P. Chhuneja    H. S. Dhaliwal    N. S. Bains    K. Singh 《Plant Breeding》2006,125(5):529-531
Micronutrient malnutrition affects a very large proportion of the world's population. For combating micronutrient malnutrition, biofortification through genetic manipulation has been proposed as an alternative to traditional fortification for increasing the bioavailable nutrient content of food crops. Wheat, being a staple food for a large section of the world's population, is targeted for increasing the Fe and Zn content in the grains. The cultivated germplasm of wheat does not have sufficient variability for grain Fe and Zn content but the wild species of wheat do show wider variation for grain micronutrient density. The analysis of Aegilops kotschyi and A. tauschii for Fe and Zn content in the grains using an atomic absorption spectrophotometer (AAS) indicated that the S and D genome species accumulate significantly higher iron and zinc in the grains than the cultivated wheats. One of the CIMMYT synthetics also had significantly higher Fe and Zn in the grains as compared with the cultivated wheats. Aegilops kotschyi as a promising source for Fe and Zn, is reported for the first time. A systematic programme to identify and utilize the additional sources for high Fe and Zn has been initiated.  相似文献   

3.
Principal component analysis has been used in this study to describe the associations among 17 traits measured on progenies developed from matings of two adapted pearl millet inbreds with three exotic pearl millets. The exotic parents were a primitive I and race, a weedy relative, and a wild relative. The first three components were calculated for these matings and the associations defined. Correlations between these components and grain yield and growth rate were also determined. The first principal component described a hybrid index in five of the six matings, and a number of other complexes of traits were determined by this component or the other two. Some were common to several matings. The first three components accounted for only 50–60% of the total variability; thus no strong association of trans was found that would hinder recombination of parental types to select agronomically desirable segregates with high grain yield or growth rate.  相似文献   

4.
M.W. Zhang  B.J. Guo  Z.M. Peng 《Euphytica》2004,135(3):315-323
Complete diallel crosses with 6 varieties of black pericarp rice and 1 variety of aromatic white rice were conducted to analyze the seed, maternal and cytoplasmic genetic effects on Fe, Zn, Mn and P contents in kernels by using a genetic model for quantitative traits of seeds in parents and their F1s and F2s. Seed, maternal as well as cytoplasmic genetic effects controlled the contents of all the mineral elements studied. The seed genetic effects were found to be more influential than the maternal genetic effects on Fe, Zn, Mn contents. Seed additive effects constituted a major component of the genetic effects whereas the seed additive along with maternal additive and dominant effects formed the main part in the inheritance of P content. The heritabilities of seed effects on all the mineral contents were highly significant (p< 0.01). The estimated values of narrow-sense heritabilites of seed genetic effects on Fe, Zn and Mn contents were high, while those of seed and maternal effects on P content were intermediate. Single plant selection and single grain selection based on the seed mineral element contents were advocated to improve the hybrid progeny. Genetic correlations showed that there existed significant genetic correlations of seed additive, seed dominance, cytoplasm, maternal additive and maternal dominance between grain characteristics such as 100-grain weight,grain length, grain width, grain shape and mineral elements Fe, Zn, Mn and P contents. Indirect selection of grain characteristics may be one of the breeding methods to select for higher contents of Fe, Zn, Mn and P in black pericarp indica rice. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

5.
Positive height-grain yield relationships exist for many cereals, but cannot be fully used in breeding because of lodging and harvestability problems in tall cultivars. Law et al. (1978) proposed a “tall-dwarf” hypothesis for wheat, in which the positive effects of minor height genes could be exploited by selecting for them in a major dwarfing gene background. The applicability of this hypothesis to pearl millet was tested by crossing a set of dwarf S1 progenies (from a single population) which varied in height onto two male-sterile lines. Mean (by S1 pollinator) hybrid grain yield was closely related to mean hybrid height (r2= 0.60) over a range of mean yields of 3.0–3.9 t ha?1 and a range of mean heights of 126–165 cm. The effect of height was expressed as an increase in grain number in one cross and as an increase in grain mass in the other, indicating the importance of background genetic effects on yield-height relationships in dwarf hybrids. The concept of “tall-dwarfs” appears to be applicable to pearl millet.  相似文献   

6.
Pearl millet (Pennisetum glaucum) is the most important cereal in crop-livestock production systems in arid and drier semi-arid environments valued for its grain and dry stover. The conventional approach of improving grain yield through greater partitioning of biomass to the grain and decreased stover yield is not a viable strategy for arid regions where biomass also needs to be improved. The current research tested the hypothesis whether biomass can be improved without extending the crop duration. The 232 F5 lines derived from a cross (J28 × RIB 335/18) were evaluated in their testcross form along with three commercial hybrids under arid zone conditions. Biomass, grain and stover yields, panicle number, grain size and grain number panicle−1 varied 1.8 to 2.7 fold in progeny testcrosses. Variation in duration of flowering time accounted for only 2% of variation in biomass, indicating that considerable scope existed for selection of testcrosses, and by implication, of F5 progenies with high biomass independent of crop duration. Stover yield accounted for 72% of differences in total biomass with remaining accounted for by grain yield. From among 92 and 132 testcrosses that had flowering time comparable to two early checks, most had significantly higher biomass, grain and stover yields than these early checks but none of the testcrosses had earliness on par with extra-early maturing hybrid HHB 67. Mean superiority of best 5% testcrosses over early checks was 58% for biomass, 68% for stover yield and 53% for grain yield. The results indicated that there are good prospects of improving biomass in arid zone pearl millet without significantly compromising crop duration.  相似文献   

7.
Crop tolerance to salinity is of high importance due to the extent and the constant increase in salt-affected areas in arid and semi-arid regions. Pearl millet (Pennistum glaucum), generally considered as fairly tolerant to salinity, could be an alternative crop option for salt affected areas. To explore the genotypic variability of vegetative-stage salinity tolerance, 100 pearl millet lines from ICRISAT breeding programs were first screened in a pot culture containing Alfisol with 250 mM NaCl solution as basal application. Subsequently, 31 lines including many parents of commercial hybrids, selected from the first trial were re-tested for confirmation of the initial salinity responses. Substantial variation for salinity tolerance was found on the basis of shoot biomass ratio (shoot biomass under salinity/ non-saline control) and 22 lines with a wide range of tolerance varying from highly tolerant to sensitive entries were identified. The performance of the genotypes was largely consistent across experiments. In a separate seed germination and seedling growth study, the seed germination was found to be adversely affected (more than 70% decrease) in more than half of the genotypes with 250 mM concentration of NaCl. The root growth ratio (root growth under salinity/control) as well as shoot growth ratio was measured at 6 DAS and this did not reflect the whole plant performance at 39 DAS. In general, the whole plant salinity tolerance was associated with reduced shoot N content, increased K+ and Na+ contents. The K+/Na+ and Ca++/Na+ ratios were also positively related to the tolerance but not as closely as the Na+ content. Therefore, it is concluded that a large scope exists for improving salt tolerance in pearl millet and that shoot Na+ concentration could be considered as a potential non-destructive selection criterion for vegetative-stage screening. The usefulness of this criterion for salinity response with respect to grain and stover yield remains to be investigated.  相似文献   

8.
In pearl millet (Pennisetum glaucum (L.) R. Br.), single cross hybrids based largely on exotic germplasm, have found very limited adoption in drought-prone arid regions mainly due to their inadequate adaptation to prevalent extremely harsh agro-climatic conditions. This study tested the hypothesis that the use of restorer parents derived from adapted landrace germplasm could be an alternative strategy in developing suitable hybrids for arid regions. Forty inbred restorer lines developed from two phenotypically diverse landraces were used to develop hybrids evaluated in this study for their performance in five typical arid zone environments between 2003 and 2007. Inbred lines from both landrace populations differed significantly in their combining ability for biomass, harvest index and grain and stover yields. A larger proportion of experimental hybrids, based on selected inbred lines, significantly outperformed the commercial checks for grain and stover yields. Increase in grain and stover yields was achieved primarily due to their higher biomass productivity, with no decline in harvest index. Choice of landrace determined the relative grain and stover productivity of their hybrids. Phenotypic differences observed in parental landraces in tillering and panicle length were also visible in their respective hybrids, indicating that characteristics of landrace parental populations were transmitted in their hybrids.  相似文献   

9.
M. Dujardin  W. W. Hanna 《Euphytica》1988,38(3):229-235
Summary An interspecific hybridization program designed to transfer gene(s) controlling apomixis from Pennisetum squamulatum Fresen. (2n=6x=54) to induced tetraploid (2n=4x=28) cultivated pearl millet, Pennisetum americanum (L.) Leeke resulted in four offtype plants, two with 27 chromosomes and two with 28 chromosomes. These plants were found among 217 spaced plants established from open-pollinated seed of an apomictic 21-chromosome polyhaploid (2n=21) plant derived from an apomictic interspecific hybrid (2n=41) between tetraploid pearl millet and Pennisetum squamulatum. It appeared that a 21- (or 20-) chromosome unreduced egg from the apomictic polyhaploid united with a 7-chromosome pearl millet (2n=2x=14) gamete to produce a 28- (or 27-) chromosome offspring. Meiotic chromosome behavior was irregular averaging from 3.60 to 4.05 bivalents per microsporocyte in the 27- and 28-chromosome hybrids. The 27- or 28-chromosome hybrids, like the 21-chromosome female parent, shed no pollen, but set from 1.8 to 28 seed per panicle when allowed to outcross with pearl millet. Progeny of the 28-chromosome hybrids were uniform and identical to their respective female parents, indicating that apomixis had been effectively transferred through the egg. In addition, a 56-chromosome plant resulting from chromosome doubling of a 28-chromosome hybrid was identified. Pollen was 68 per cent stainable and the plant averaged 2.3 selfed seeds per panicle. Chromosomes of the 56-chromosome plant paired as bivalents (x=10.67) or associated in multivalents. Three to nine chromosomes remained unpaired at metaphase I. Multiple four-nucleate embryo sacs indicated the 56-chromosome hybrid was an obligate apomict. The production of 27-, 28-, and 56-chromosome hybrid derivatives were the results of interspecific hybridization, haploidization, fertilization of unreduced apomictic eggs, and spontaneous chromosome doubling. These mechanisms resulted in new unique genome combinations between x=7 and x=9 Pennisetum species.  相似文献   

10.
F. Ahmad  A. Comeau 《Euphytica》1990,50(3):181-190
Summary Eight grain pearl millet (2n=14) accessions were crossed as male to hexaploid spring wheat cv. Fukuho (2n=6x=42). An average of 80% wheat pistils showed pearl millet pollen tube entry in the ovules, compared to 56% in wheat x maize cv. Seneca 60 cross. Of the 15 embryos, obtained through in vitro immature seed culture from wheat x pearl millet crosses, 3 plantlets were produced and grown to maturity. These three were of the somatic chromosome constitution 2n=42, 21 and 22, respectively. Haploid wheat plant (2n=21) apparently originated from pearl millet chromosome elimination during embryogenesis. The 22 chromosome plant had retained a single pearl millet chromosome at tillering stage, but this chromosome was eliminated from pollen mother cells prior to and also during gamete formation. The significance and potential uses of this wide cross is discussed.  相似文献   

11.
Farmers in western Rajasthan (north‐west India) produce and maintain their landrace populations of pearl millet through their own distinct seed management practices. The objective of this study was to characterize morphological and agronomic variability of different traits between and within three farmers' populations using quantitative‐genetic parameters. Populations examined were a typical landrace and two modified landraces, which were generated through farmer introgression of modern varieties with different levels of subsequent selection. From these three populations, 100 random full‐sib progenies were evaluated in field trials at two locations in western Rajasthan over two years. Significant genetic variation existed within the three populations. Estimates of heritability were moderate to high for all observed traits. Predicted selection response for grain yield across environments was 1.6% for the typical landrace and 2.2% for both the modified landraces. Results suggest that the introgression of modern varieties into landraces had increased the genetic diversity. Therefore, farmers' current breeding activities could open up new resources for plant breeding programmes aiming at plant improvement for the semiarid zones of India.  相似文献   

12.
In field and greenhouse experiments Ethrel (2-chloroethyl phosphonic acid) was tested for its male garnetocidal effects on pearl millet (Pennisetum americanum) and its subsequent effects on ergot development. Application of Ethrel at 2000 ppm at late boot or early protogyny was the most effective for inducing male sterility in the hybrid, EJ 104. Female fertility in a male sterile line, however, was not affected by Ethrel treatment. Ethrel at 2030 ppm applied at ihe late boot stage resulted1 in partial paniele exsertion, and reduced plant height anc. panide length. In vitro Ethrel (2000 ppm) completely inhibned pollen germination but did not affect germination of conidia of Claviceps fusiformis, the causal agent of ergot of pearl millet. Ergot resistance or susceptibility in pearl millet lines was not affected., probably because Ethrel could not induce complete male sterility.  相似文献   

13.
A pearl millet mapping population from a cross between ICMB841 and 863B was studied for DNA polymorphism to construct a genetic linkage map, and to map genomic regions associated with grain and stover yield, and aspects of drought tolerance. To identify genomic regions associated with these traits, mapping population testcrosses of 79 F3 progenies were evaluated under post-flowering drought stress conditions over 2 years and in the background of two elite testers. A significant genotype × drought stress treatment interaction was evident in the expression of grain and stover yield in drought environments and in the background of testers over the 2 years. As a result of this, genomic regions associated with grain and stover yield and the aspects of drought tolerance were also affected: some regions were more affected by the changes in the environments (i.e. severity and duration of drought stress) while others were commonly identified across the drought stress environments and tester background used. In most instances, both harvest index and panicle harvest index co-mapped with grain yield suggesting that increased drought tolerance and yield of pearl millet that mapped to these regions was achieved by increased partitioning of dry matter from stover to the grains. Drought stress treatments, years and testers interactions on genomic regions associated with grain and stover yield of pearl millet are discussed, particularly, in reference to genetic improvement of drought tolerance of this crop using marker-assisted selection.  相似文献   

14.
华北地区谷子产量与农艺性状的综合评价分析   总被引：7，自引：0，他引：7  
对华北夏谷区谷子农艺性状与产量性状进行灰色关联度分析,探讨主要农艺性状对产量的影响,为谷子优良种质资源利用及高产品种选育提供依据。以2016年全国谷子品种区域适应性联合鉴定华北夏谷区常规组参试的17个品种（系）为材料,采用相关分析和灰色关联度分析相结合的方法,对产量相关8个农艺性状进行综合评价。结果表明,供试材料9个农艺性状均存在变异,变异幅度2.69%~11.71%;穗粒重、单穗重、出谷率与产量呈显著正相关;9个农艺性状对谷子产量影响大小依次为穗粗>单穗重>穗粒重>千粒重>株高>出谷率>穗长>生育期,穗粗、单穗重和穗粒重对产量的影响最大。说明谷子产量育种应重视大穗、大粒、穗粒重高的种质资源利用,并适当关注株高。  相似文献   

15.
L. Marchais  S. Tostain 《Euphytica》1997,93(1):97-105
Crosses between pearl millet lines and Pennisetum ramosum, P. schweinfurthii, P. squamulatum or Cenchrus ciliaris were observed for the frequency and development of zygotes, the possibility of embryo rescue, and the fertility of F1 hybrids obtained. Eight per cent of the ovules from diploid millet × P. ramosum crosses showed small embryos which could not be rescued. However, 59% of the ovules from tetraploid millet × P. ramosum crosses showed well-developed embryos that were easy to rescue 14 days after pollination. F1 hybrids were male sterile but female fertile when pollinated by diploid millet. Both diploid and tetraploid millet ovules showed the presence of hybrid zygotes after pollination with P. schweinfurthii at rates ranging from 25% to 45%. The diploid millet× P. schweinfurthii hybrid zygotes often developed almost normal seeds giving, without embryo rescue, totally sterile plants. The tetraploid millet × P. schweinfurthii hybrid embryos were normal but the endosperm was severely defective. A hybrid obtained by embryo rescue was totally sterile. A diploid millet-P. schweinfurthii amphidiploid was obtained by somatic embryogenesis associated with colchicine treatment during callogenesis. This amphiploid plant was male sterile, but gave many seeds when pollinated by a tetraploid millet and few seeds when pollinated by a diploid millet. P. squamulatum pollinating diploid millets produced proembryos with large undifferentiated endosperms in 73% of the ovules. A normal seed set was observed on tetraploid millets pollinated by P. squamulatum and the resulting F1 hybrids were partially male and female fertile. Backcrosses of these hybrids were much more fertile when pollination was from a tetraploid millet rather than from a diploid millet. C. ciliaris pollinating a diploid millet showed, in 60% of the ovules, proembryos and endosperms similar to those observed with P. squamulatum and no hybrid could be rescued. Crosses with a tetraploid millet could not be attempted due to the pistil-pollen incompatibility of tetraploid millets available with C. ciliaris. Ploidy levels of mating partners do not seem to influence pistil-pollen compatibility, but play a major role in post-zygotic abortion. With adequate ploidy levels of parents, and embryo rescue, it seems that the pearl millet gene pool can be considerably enlarged by germplasm from many other species.  相似文献   

16.
为了明确燕麦种质资源矿质元素含量的多样性,采用原子吸收分光光度法测定了燕麦种质铜（Cu）、铁（Fe）、锌（Zn）、镁（Mg）和钙（Ca）元素的含量,进行遗传变异、聚类和相关分析。结果表明：供试材料的Cu、Fe、Zn、Mg和Ca元素含量具有丰富的多样性,平均多样性指数为2.022,平均变异系数为29.775%。筛选到Cu含量高的种质有休眠燕麦、加5、坝莜1号、YS0404、v5和v18;Fe含量高的种质有太丰、夏莜麦、9418、蒙燕2号和shadow;Zn含量高的种质有ハヤテ和坝莜9号;Mg含量高的种质有ハヤテ和莜麦4400;Ca含量高的种质有v18、鉴19和白燕7号。Zn、Fe、Mg的含量均较高的种质有ハヤテ、6518、加9、MARION、坝莜8号、晋燕2004、坝莜9号和品五。燕麦种质Cu与Zn含量呈显著正相关,Ca与Fe含量间呈极显著负相关。  相似文献   

17.
Summary To determine the distribution and geographic specificity of sterility maintainers in pearl millet, Pennisetum americanum (L.) Leeke, 428 diverse pearl millet germplasm accessions representing variation from 12 countries were crossed with a male-sterile line 5141A. The F1 hybrids were classified as male-fertile or male-sterile based on the seed set on bagged ear heads and an other morphology. Among these, 87 (20.3%) were classified as male-fertile, 32 (7.5%) as male-sterile, 282 (65.9%) as segregating for male-fertile/male-sterile and 27 (6.3%) behaved as male-fertile in the rainy and male-sterile in the postrainy season. Restorer lines were distributed in all the countries studied except Cameroon and USSR. Maintainer lines were observed from six countries but were concentrated in India. These maintainer lines differ from one another in several morphological and agronomic characters such as flowering, plant height, spike length and grain size. They may prove to be useful sources of material for generating new male-sterile lines. The restorers can be used to produce commercial hybrids.Submitted as J.A. No. 719 by the International Crops Research Institute for the Semi-Arid Topics (ICRISAT).  相似文献   

18.
A set of 22 pearl millet inbred lines including the parents of eleven mapping populations, was screened with 627 markers including 100 pearl millet genomic SSRs (gSSRs), 60 pearl millet EST-SSRs (eSSRs), 410 intron sequence haplotypes (ISHs), and 57 exon sequence haplotypes (ESHs). In all, 267 (59%) of the markers were informative for at least one of the 11 mapping populations, which segregate for traits like drought and salinity tolerance; host plant resistance to downy mildew, rust and blast; fertility restoration and sterility and maintenance of cytoplasmic male sterility etc. An average of 116 polymorphic markers was identified per mapping population. The average PIC values and number of profiles (P) per polymorphic marker were: gSSRs (PIC = 0.62, P = 6.1), ISHs (PIC = 0.39, P = 2.6), eSSRs (PIC = 0.36, P = 3.1) and ESHs (PIC = 0.35, P = 3.1). A high correlation (r > 0.97, P < 0.05) was observed between the patterns of diversity exposed by the different marker systems. The polymorphic markers identified are suitable for the de novo construction, or the supplementation of pearl millet linkage maps. The genetic relationships identified among the panel of inbred lines may be useful in designing strategies to improve the use of available genetic variation in the context of pearl millet breeding.  相似文献   

19.
Iron and zinc grain density in common wheat grown in Central Asia   总被引：5，自引：0，他引：5  
Sixty-six spring and winter common wheat genotypes from Central Asian breeding programs were evaluated for grain concentrations of iron (Fe) and zinc (Zn). Iron showed large variation among genotypes, ranging from 25 mg kg−1 to 56 mg kg−1 (mean 38 mg kg−1). Similarly, Zn concentration varied among genotypes, ranging between 20 mg kg−1 and 39 mg kg−1 (mean 28 mg kg−1). Spring wheat cultivars possessed higher Fe-grain concentrations than winter wheats. By contrast, winter wheats showed higher Zn-grain concentrations than spring genotypes. Within spring wheat, a strongly significant positive correlation was found between Fe and Zn. Grain protein content was also significantly (P < 0.001) correlated with grain Zn and Fe content. There were strong significantly negative correlations between Fe and plant height, and Fe and glutenin content. Similar correlation coefficients were found for Zn. In winter wheat, significant positive correlations were found between Fe and Zn, and between Zn and sulfur (S). Manganese (Mn) and phosphorus (P) were negatively correlated with both Fe and Zn. The additive main effects and multiplicative interactions (AMMI) analysis of genotype × environment interactions for grain Fe and Zn concentrations showed that genotype effects largely controlled Fe concentration, whereas Zn concentration was almost totally dependent on location effects. Spring wheat genotypes Lutescens 574, and Eritrospermum 78; and winter wheat genotypes Navruz, NA160/HEINEVII/BUC/3/F59.71//GHK, Tacika, DUCULA//VEE/MYNA, and JUP/4/CLLF/3/II14.53/ODIN//CI13431/WA00477, are promising materials for increasing Fe and Zn concentrations in the grain, as well as enhancing the concentration of promoters of Zn bioavailability, such as S-containing amino acids.  相似文献   

20.
One population of pearl millet (Pennisetum glaucum (L.) R. Br.) highly susceptible to downy mildew (Sclerospora graminicola (Sacc.) Schroet.) was subjected to two cycles of recurrent selection for downy mildew resistance using a modified greenhouse screening method. The response to selection was evaluated under greenhouse and field conditions using 50 random S1 progenies and 50 random full-sib progenies from each cycle bulk. Significant progress over cycles of selection was observed in all evaluation trials. These results demonstrated that, in a susceptible population, recurrent selection effectively increased the level of resistance to downy mildew. The modified greenhouse method for assessing resistance to downy mildew effectively differentiated genotypes and had the advantages of greater rapidity and suitability for use throughout the year, independent of season. A rapid decline of genotypic variance was observed in advanced cycles of selection, indicating that a small number of genes controls downy-mildew resistance in this population. The comparison of genotypic and error variance components from S1 progenies and full-sib progenies suggested that full-sib progenies can be used successfully in recurrent selection for increased downy-mildew resistance.  相似文献   

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