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1.
Plant height is one of the most important agronomic traits in sorghum with its relevance for biomass, grain yield, fodder and lodging. To understand its genetic basis, the quantitative trait loci (QTL) were identified using a recombinant inbred line (RIL) population consisting of 168 RILs derived from the cross between the two sorghum inbred lines 296B (dwarf) and IS18551 (tall) over six seasons. Two major QTL were identified one each on chromosomes SBI-06 and SBI-07 corresponding to the Dw2 and Dw3 gene loci together accounting 41 % plant height variation. In addition, a morphological bloom trait locus which remained unlinked in the linkage map was found to be significantly linked with plant height in single marker analysis explaining 22 % of the trait variation. By comparing the map positions of Dw1, Dw2 and Dw3, the new locus for plant height linked with bloom is proposed as Dw4 locus. Both SSR and the morphological bloom loci linked with height QTL of the present study can be employed as effective tools in marker-assisted breeding for rapid conversion of selected inbred parent lines either as dwarf seed (male sterile) parents or taller pollinators for hybrid seed industry, or for developing high biomass lines in sweet sorghum for exploitation as high bio-fuel crop.  相似文献   

2.
The genetic diversity of 65 accessions of sorghum [Sorghum bicolor (L.) Moench] collected from various farmers and germplasm lines from ICRISAT-Kenya were analyzed. Simple sequence repeats (SSR) markers were used in order to determine the extent and distribution of its genetic diversity. Twenty-nine (29) SSRs markers were polymorphic and a total of 192 alleles were detected which showed diversity. The number of alleles per primer ranged from 2 to 17, with an average of 6.62. The range of polymorphism information content (PIC) ranged from 0.03 to 0.86, with total average of 0.82. According to the results analyzed, estimates of the mean allelic pattern across the two populations was generated; expected heterozygosity (He; 0.45, 0.54), average observed alleles (Na; 3.40, 6.20), number of private allele (0.23, 3.03), and Shannon information index (I; 0.85, 1.13) for farmer and ICRISAT-Kenya germplasm, respectively. The expected heterozygosity (He) varied from 0 to 0.26 with an average of 0.05. The Neighbor-joining phenogram based on Nei’s genetic distance grouped the 65 accessions into three main groups. The analysis of molecular variance (AMOVA) revealed that 99% of the total genetic variation was within accessions in a population whereas the genetic variation among populations in accessions accounted for 1% of the total genetic variation. Genetic diversity in ICRISAT sorghum material compared to the farmer’s collection suggested little infiltration of improved germplasm to the farmers.  相似文献   

3.
以粒用高粱和甜高粱为材料,对甜高粱与粒用高梁不同时期茎秆的可溶性糖含量、蔗糖含量、果糖含量及SS、SPS酶活力进行比较,结果表明:茎秆中的可溶性糖含量、果糖含量在完熟期甜高粱高于粒用高粱,乳熟期茎秆中蔗糖含量甜高粱高于粒用高粱;两种高粱类型的SPS酶活力变化趋势基本相似,从乳熟期到完熟期粒用高粱茎秆中的SPS酶活力明显增高,SS酶活力在粒用高粱茎秆中随生育期呈上升趋势,甜高粱茎秆中SS酶活力到乳熟期达到最大,明显高于粒用高粱.对糖含量与其相关代谢酶活力的相关性分析表明:甜高粱茎秆中利用SPS酶合成蔗糖的效率要高于粒用高粱;两种类型高粱的SS酶活力与其茎秆中的果糖含量存在明显差异,SS的作用模式不同.  相似文献   

4.
甜高粱蔗糖合酶表达与蔗糖积累的相关分析   总被引：4，自引：0，他引：4  
以甜高粱为原料生产酒精是一种有潜力的生物能源途径,了解甜高粱蔗糖积累机理对生物能源开发具有重要意义。以两个甜高粱品种为材料,利用Western blotting技术检测高粱叶片和茎秆中蔗糖合酶(Sucrose Synthase, SS)的表达,分析其与蔗糖积累的相关性。结果表明,甜高粱叶片和茎秆中的SS蛋白质表达量在发育早期(拔节期、抽穗期)较低,发育后期(开花期、灌浆期和腊熟期)明显升高,在开花期最高。同2个普通高粱品种相比,在发育后期2个甜高粱品种叶片和茎秆中SS的表达明显增加,且与茎秆中的蔗糖积累相关,推测这是甜高粱与普通高粱蔗糖含量差异的重要原因。试验结果为选育甜高粱品种和提高茎秆蔗糖含量提供了一条可能的策略。  相似文献   

5.
Association mapping is widely used for detecting QTLs in higher plants. In the present study a synthetic sorghum population containing 119 representative samples, including 43 sweet and 76 grain sorghum accessions originating mainly from China, USA and India, were genotyped using 51 simple-sequence repeat (SSR) markers. Linkage disequilibrium (LD) of pair-wise loci and population structure were analyzed, followed by association analysis of SSR loci and 3 sugar yield related traits using the TASSEL general linear model program. Results showed that: (i) different degrees of LD occurred among syntenic markers and also among nonsyntenic markers, indicating historical recombination among sorghum linkage groups; (ii) significant LD extended up to 7.31 cM; (iii) the collection of accessions was composed of three subgroups; (iv) four marker loci were associated with stalk sugar concentration, fresh stalk weight and stalk juice weight measured in different growing environments and could be used, therefore, in future marker assisted breeding programs. Several loci were also associated with two or more traits simultaneously, which might be due to tight linkage between different genes affecting these traits and/or pleiotropy. In addition, some associated markers were located close to QTLs previously mapped in family-based linkage mapping analyses.  相似文献   

6.
Y. Peng    K. F. Schertz    S. Cartinhour  G. E. HART 《Plant Breeding》1999,118(3):225-235
A restriction fragment length polymorphism (RFLP) linkage map of Sorghum bicolor (L.) Moench was constructed in a population of 137 F6-8 recombinant inbred lines using sorghum, maize, oat, barley and rice DNA clones. The map consists of 10 linkage groups (LGs) and 323 markers, 247 of which (76.5%) were ordered at a LOD score ≥ 3.0. The LGs comprise from 61 (LG A) to 13 markers (J), which range in length from 205 (A) to 55 cM (J) and have a combined total length of 1347 cM. Highly significant distorted segregation was detected at all of the 38 loci in a 103-cM segment of LG A, the allelic ratios in the segment ranging from approximately 3:1 (one end) to 19:1 (middle) to 2:1 (other end). Duplicated loci located in different LGs have been mapped with 55 of the 295 DNA probes used in the study (18.6%). The distribution of these loci does not provide support for the hypothesis that Sorghum bicolor (L.) Moench is of tetraploid origin. Comparison of the map with RFLP maps of maize, rice, and oat produced evidence for sorghum-maize LG rearrangements and homoeologies not reported previously, including evidence that: (1) a segment of maize 5L and a segment of 5S may be homoeologous to sorghum LGA; (2) maize LGs 4 and 6 are partly homoeologous to sorghum LGE; (3) the short arm of maize LG 2 is partly homoeologous to sorghum LGF; (4) maize LG 4 may be partly homoeologous to sorghum LG G; (5) maize LG 5 and sorghum LG G contain a larger amount of homoeologous genetic material than previously indicated; and (6) a short segment of maize LG 1 may be homoeologous to a short segment of sorghum LG I.  相似文献   

7.
The hybrid vigor typical of F1 cultivars is used to boost biomass production of sorghum (Sorghum bicolor (L.) Moench). The high dry-matter yielding F1 cultivar Kazetachi uniquely shows extremely late flowering and a long culm, and is greatly different from its parents. We investigated the genetic mechanisms underlying these phenotypes by quantitative trait locus (QTL) analysis of recombinant inbred lines derived from a male-fertile line and a restorer line and grown in 3 years. QTL analysis for six traits (days-to-heading, culm length, culm width, culm number, panicle length, panicle number) revealed that the unique phenotypes of the F1 plants were controlled by the genetic combination of 12 or more QTLs detected in at least 2 years. Two putative QTLs for days-to-heading (qDH1 on SBI-01 and qDH6 on SBI-06) would strongly affect the other phenotypes because of their co-localization with QTLs for other traits, as supported by significant phenotypic correlations. These QTLs would be useful for understanding the association of plant type with biomass production in sorghum.  相似文献   

8.
A study on marker-assisted selection (MAS) for the rf1 gene, which controls pollen sterility in the sorghum A1 cytoplasm, was conducted on the offspring population of two crosses between a maintainer line, BTx-622, and two sweet sorghum lines, BJ-299 and Lunen-2, to test the effectiveness of the MAS method and develop maintainer lines with sweet and juicy stalks and corresponding cytoplasmic-nuclear male sterility (CMS) lines. The simple sequence repeat marker Xtxp18 exhibited a high accuracy (95.098 %) for selecting recessive homozygotes for the rf1 gene. The segregation ratio matched the expected ratio calculated according to the reported genetic distance in the F2 population of the two crosses used. Finally, four excellent maintainer lines/CMS line pairs (F5/BC3) with high stalk juice and stalk juice sugar contents were developed. The MAS method based on Xtxp18 for the sorghum rf1 gene could be used for hybrid breeding programs at a low cost in the future.  相似文献   

9.
Summary A genetic diversity analysis in a collection of 171 non-restorer lines of sorghum (Sorghum bicolor (L.) Moench) using D2 technique and canonical variate analysis indicated that considerable variation in grain yield has been added to the collection by the addition of lines derived from random mating populations. The efficiency of D2 and canonical variate techniques in distinguishing extremely diverse genotypes was confirmed. However, the two techniques showed weak correspondence in their clusters. The F1 hybrids of 15 diverse lines exhibited no relationship between heterosis or per se performance of crosses and diversity in their parents. Therefore, traditional plant breeding methods are being advocated.Approved by ICRISAT as Journal Article no. 435.  相似文献   

10.
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11.
Knowledge of the origin, organization and nature of the cassava (Manihot esculenta Crantz) germplasm collection in Brazil is incomplete due to lack of critical information on several aspects of the collection. This study verifies the utility of SSR-primed PCR markers for germplasm assessment and then utilizes these markers as well as RAPD's to characterize the Brazilian collection. We specifically address the following questions: 1)what is the relationship of morphologically closely related species to cultivated cassava? 2) What is the genetic diversity of cultivars within and between different habitats in Brazil? 3) Do agronomic traits and molecular markers reveal the same relationship among cassava accessions? 4) How complete is the Brazilian cassava collection and how well is it represented in the Word Core Collection of cassava, maintained by CIAT? Results of the interspecific studies of cassava and its wild relatives confirms the close relationship of cassava, Manihot esculenta ssp. esculenta to Manihot esculenta ssp. flabellifolia as well identifying several other closely related wild species. Next, PCR-based markers indicate a strong grouping of varieties related to the region of cultivation in Brazil. Moreover, important regions such as Cerrados and Amazon are relatively poorly represented in germplasm collections. Interestingly, the relationships of accessions based on agronomic traits are not fully congruent with relationships revealed with RAPD markers. Finally, the genetic diversity of the Brazilian cassava collection is not fully represented in the Core of the Word Core Collection of CIAT.  相似文献   

12.
Plant height (PHT), stem and leaf fresh weight (SLFW), juice weight (JW) and sugar content of stem (Brix) are important traits for biofuel production in sweet Sorghum. QTL analysis of PHT, SLFW, JW and Brix was conducted with composite interval mapping using F2 and F2:3 populations derived from the cross between grain Sorghum (Shihong137) × sweet Sorghum (L-Tian). Three QTLs controlling PHT were mapped on SBI-01, SBI-07 and SBI-09 under four different environments. These QTLs could explain 10.16 to 45.29% of the phenotypic variance. Two major effect QTLs on SBI-07 and SBI-09 were consistently detected under four environments. Eight QTLs controlling SLFW were mapped across three environments and accounted for 5.49–25.36% of the phenotypic variance. One major QTL on SBI-09 located between marker Sb5-206 and SbAGE03 was observed under three environments. Four QTLs controlling Brix were identified under two environments and accounted for 11.03–17.65% of the phenotypic variance. Six QTLs controlling JW were detected under two environments, and explained 6.63–23.56% of the phenotypic variance. QTLs for JW on SBI-07 and SBI-09 were consistent in two environments showing higher environmental stability. In addition, two chromosome regions on SBI-07 and SBI-09 were identified in our study having major effect on PHT, SFLW and JW. The results would be useful for the genetic improvement of sweet Sorghum to be used for biofuel production.  相似文献   

13.
Forage sorghum cultivars grown in India are susceptible to various foliar diseases, of which anthracnose, rust, zonate leaf spot, drechslera leaf blight and target leaf spot cause severe damage. We report here the quantitative trait loci (QTLs) conferring resistance to these foliar diseases. QTL analysis was undertaken using 168 F7 recombinant inbred lines (RILs) of a cross between a female parental line 296B (resistant) and a germplasm accession IS18551 (susceptible). RILs and parents were evaluated in replicated field trials in two environments. A total of twelve QTLs for five foliar diseases on three sorghum linkage groups (SBI-03, SBI-04 and SBI-06) were detected, accounting for 6.9–44.9% phenotypic variance. The morphological marker Plant color (Plcor) was associated with most of the QTL across years and locations. The QTL information generated in this study will aid in the transfer of foliar disease resistance into elite susceptible sorghum breeding lines through marker-assisted selection.  相似文献   

14.
Teosinte comprises different Zea species (Zea mays, Zea diploperennis, Zea perennis, Zea luxurians) that can be crossed with cultivated maize (Z. mays ssp. mays). Nine microsatellites from maize were applied to different teosinte species in order to evaluate their usefulness in markerbased exploitation of these genetic resources. The same microsatellites were tested with rye, barley, and sorghum as potential molecular markers for these species. Almost all microsatellite × teosinte combinations yielded polymerase chain reaction (PCR) fragments in the range of cultivated maize. Using an F2 population of a cross between maize inbred A188 and an individual of Zea mays ssp. mexicana, amplification products for maize and teosinte originated from the same genomic location for each of nine microsatellites investigated. PCR fragments of reduced intensity were generally obtained by applying maize microsatellites to rye, barley and sorghum. Polymorphisms among accessions within teosinte (sub)species occurred frequently. In contrast, no polymorphisms were obtained within rye, barley, and sorghum. Hence, application of maize microsatellites to teosinte for fingerprinting or marker-assisted introgression of genomic regions from teosinte into cultivated maize appears promising.  相似文献   

15.
The accumulation of soluble carbohydrates in vegetative parts of sweet sorghum ( Sorghum bicolor (L.) Moench.) represents an intermediate reserve pool for grain filling as well as an irreversible storage up to maturity. In order to study the effect of Sterility on soluble sugar accumulation in vegetative parts, two cytoplasmic male sterile (CMS) lines of sweet sorghum were compared with their corresponding fertile mamtainers for non-structural carbohydrate concentrations in shoots. Plants were harvested at four different physiological stages. The lines showed significant differences in the yield of non-structural carbohydrates. At maturity, the yields of soluble carbohydrates from vegetative parts of the two sterile lines were 93 % and 43 % higher than the yield of the two corresponding fertile lines. At that stage, sucrose represented about 80 % of total soluble carbohydrates and the higher yield of soluble carbohydrates of sterile lines was mainly due to the higher yield of sucrose. This indicates that the yield of extractable carbohydrates, especially sucrose, in vegetative parts of sweet sorghum could be considerably improved by using sterile lines which are utilized in hybrid production.  相似文献   

16.
Sweet sorghum (Sorghum bicolor [L.] Moench) is a prospective bioethanol feedstock source. Four high-biomass and sweet sorghum male lines and three grain sorghum female lines were intercrossed using Design II mating. Parents and hybrids were evaluated to (a) identify genetic sources to improve biofuel traits, and (b) determine the inheritance of biofuel and morpho-agronomic traits. Total soluble sugars (TSS) per plant were determined using juice weight (JW) and Brix (°Bx). Plant height (PH), biomass (BM) and stalk diameter (SD) were also measured. Mean hybrid performance for PH, JW, TSS and BM was higher than the male parent means. Three male parents exhibited positive and significant general combining ability (GCA) for at least three traits. Among males, PI185672 showed the highest GCA for PH, °Bx and BM, while No. 08 exhibited the greatest GCA for JW and TSS. Most hybrids exhibited overdominance-driven high-parent heterosis for all traits except SD. Trait broad-sense heritability ranged from 0.71 (BM) to 0.93 (PH). Results revealed that biofuel traits could be substantially improved through breeding, which will contribute to enhanced bioethanol production.  相似文献   

17.
A factor frequently identified as a key to understanding sorghum [Sorghum bicolor (L.) Moench feed value to ruminant animals is rate of starch digestion. Recent research in corn (Zea mays L.) has established a strong ability to predict rumen starch degradation from grain physical and chemical parameters. It was therefore important to determine whether similar relationships could be established in sorghum. The objectives of this study were to determine: 1) range of variation for12-hour in vitro dry matter disappearance (IVDMD), chemical, and physical grain quality parameters among 16sorghum conversion lines; and 2) to establish the strength of the relationships of these characters. Entries were grown at Ithaca, Nebraska in 1991 and 1992 in a randomized complete block with four replications. Line effects were significant for 12-hour IVMVD, crude protein, oil, starch, individual seed weight, and hardness. The only traits significantly correlated with 12-hour IVDMD were crude protein and hardness, with r≤–0.32 for testa and non-testa-containing lines. Stepwise regression similarly revealed poor predictive ability for any of the traits on12-hour IVDMD. Unlike corn, prediction of digestibility from simply measured physical parameters was not possible in this set of16 sorghum lines. However, the lack of strong relationships provides opportunity to select lines with unique combinations of traits for individual targeted needs or markets. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

18.
A total of 415 sorghum (Sorghum bicolor (L.) Moench) accessions representing different regions of Ethiopia, Eritrea and a group of introduced lines were evaluated for 15 quantitative characters to determine the extent and geographical pattern of morphological variation. The extent of variation was highly pronounced for agronomically important characters for sorghum. These characters included plant height, days for 50% flowering, peduncle exsertion, panicle length and width, number and length of primary branches per panicle and thousand seed weight. Significant regional variation was also observed for most of the characters. The results implied that environmental factors such as altitude, rainfall, temperature and growing period are important in regional variation. Mean for plant height and for days for 50% flowering showed clinal variation along the gradients of rainfall pattern and growing period in Ethiopia. Moreover, there were significant positive correlation coefficients between most of the characters. This included the correlation between agronomic characters of primary interest in sorghum breeding such as plant height and days for 50% flowering and also between various characters and the altitude of the collection sites. The implications of the results in plant breeding, germplasm collection and conservation as well as the probable sources of the wide range of variation are discussed. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

19.
The genetic diversity among an international collection of 40 maize accessions has been evaluated using DNA ISSR fingerprinting. Among the 180 ISSR markers scored by 15 primers, 161 markers (89.59%) were polymorphic and 19 were unique in 16 accessions. A cluster tree based on the average distance coefficients and the Dice similarity indices divided the accessions into three major groups, each including clusters of accessions assigned to their subspecies. However, a low level of genetic differentiation among the accessions was demonstrated by the STRUCTURE analysis of ISSR data in agreement with the low gene flow (Nm) value among the accessions. A scatter diagram of the principal component analysis (PCA) based on ISSR data analysis revealed that the accessions were differentiated into three groups comparable to those produced by the cluster analysis, in which some accessions of the same subspecies showed a close similarity to each other. A scatter diagram of the principal coordinate analysis (PCoA) based on the drought tolerance indices (DTIs) showed that nine genetically similar accessions share drought tolerance characteristics; these include four of subsp. indurata, three of subsp. everata, and two of subsp. indentata. An abundance of unique ISSR alleles found in the 16 accessions, including the nine drought-tolerant accessions, represents rich untapped genetic resources and these accessions may be exploited in the future breeding of maize commercial lines.  相似文献   

20.
甜高粱茎秆含糖量遗传研究进展   总被引：3，自引：0，他引：3  
甜高粱(Sorghum bicolor)是普通粒用高粱的一个变种。与粒用高粱相比,甜高粱育种研究进展相对缓慢,特别是茎秆含糖量高的亲本系创造比较滞后。开展甜高粱茎秆含糖量的遗传研究,对甜高粱亲本系选育及杂交种组配具有重要意义。本文从茎秆含糖量的评价指标入手,分别对茎秆含糖量的遗传与子粒产量及其他性状的关系、基因定位等方面的相关研究结果进行了系统地概括和归纳,并分析了当前茎秆含糖量研究的热点和亟待解决的问题。  相似文献   

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