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1.
Soybean seed includes various bioactive substances. Also, they contain a variety of antinutritional factors including lipoxygenase, Kunitz trypsin inhibitor (KTI), lectin, and 7S α' subunit proteins. The genetic removal of these proteins will improve the nutritional value of soybean seed. The objective of this research was to breed new soybean with tetra recessive alleles (lox1lox2lox3/lox1lox2lox3‐ti/ti‐le/le‐cgy1/cgy1) for lipoxygenase, KTI, lectin, and 7S α' subunit proteins. Seven parents were used to breed tetra null strain. SDS‐PAGE and Western blot analysis were used to determine the presence or absence of lipoxygenase, 7S α' subunit, KTI, and lectin proteins in mature seed. Tetra null soybean line has a purple flower, determinate growth habit, tan pod, and yellow seed coat colour. Stem height of the breeding line was 62.3 cm. The 100‐seed weight of the breeding line was 27.1 g and yield (t/ha) was 2.84. This is the first soybean strain with lox1lox2lox3/lox1lox2lox3‐ti/ti‐le/le‐cgy1/cgy1 genotype (absence of lipoxygenase, KTI, lectin, and 7S α' subunit proteins).  相似文献   

2.
Vitamin A deficiency in humans is a widespread health problem. Quality protein maize (QPM) is a popular food rich in lysine and tryptophan, but poor in provitamin A (proA). Here, we report the improvement of an elite QPM inbred, HKI1128Q for proA using marker‐assisted introgression of crtRB1‐favourable allele. HKI1128 was one of the parental lines of three popular hybrids in India and was converted to QPM in our earlier programme. Severe segregation distortion for crtRB1 was observed in BC1F1, BC2F1 and BC2F2. Background selection by 100 SSRs revealed mean recovery of 91.07% recurrent parent genome varying from 88.78% to 93.88%. Across years, introgressed progenies possessed higher mean β‐carotene (BC: 9.22 µg/g), β‐cryptoxanthin (BCX: 3.05 µg/g) and provitamin A (proA: 10.75 µg/g) compared to HKI1128Q (BC: 2.26 µg/g, BCX: 2.26 µg/g and proA: 3.38 µg/g). High concentration of essential amino acids, viz. lysine (mean: 0.303%) and tryptophan (0.080%) in endosperm, was also retained. Multi‐year evaluation showed that introgressed progenies possessed similar grain yield (1,759–1,879 kg/ha) with HKI1128Q (1,778 kg/ha). Introgressed progenies with higher lysine, tryptophan and proA hold immense potential as donors and parents in developing biofortified hybrids.  相似文献   

3.
Vitamin A deficiency is one of the major health problems worldwide. Traditional yellow maize possesses very low provitamin A (proA) concentration in endosperm. The influence of rare alleles of β‐carotene hydroxylase (crtRB1) and lycopene epsilon cyclase (lcyE) genes capable of enhancing proA concentration was studied in four BC2F2 populations generated using subtropical inbreds and CIMMYT‐HarvestPlus lines. The occurrence of severe segregation distortion for crtRB1 gene was observed, while lcyE gene was segregated as per Mendelian ratio. Genotype with favourable allele of crtRB1 (CC) had a significant effect on β‐carotene (BC) (7.9‐fold), β‐cryptoxanthin (BCX) (twofold) and proA (5.5‐fold) accumulation, compared to unfavourable genotype (C+C+). Genotype with favourable allele of lcyE (LL) showed 2.1‐fold, 1.6‐fold and twofold significant enhancement in BC, BCX and proA, respectively, over unfavourable genotype (L+L+) in pooled analysis. Of the nine genotypes, double homozygote (CC/LL) had the highest mean BC (12.60 μg/g), BCX (4.44 μg/g) and proA (14.82 μg/g), and combined effect was significantly better than individual gene effects or any other combinations. The information generated here would be useful in designing strategy for proA enrichment in subtropical maize.  相似文献   

4.
Using the advanced backcross quantitative trait loci (AB‐QTL) strategy, we successfully transferred and mapped valuable allelic variants from the high β‐glucan (BG) accession IAH611 (PI 502955), into the genome of cultivar ‘Iltis’. By backcrossing one BC1F1 plant to ‘Iltis’, we developed two BC2F2‐6 populations A and B, comprising 98 and 72 F2‐individuals, respectively. Genotyping of BC2F2 individuals with predominantly AFLP markers resulted in 12 linkage groups with a map size of 455.4 cM for Population A and 11 linkage groups with a map size of 313.5 cM for Population B. Both populations were grown at three sites in Germany over a three‐year period. Individuals were then phenotyped for 13 traits including grain yield (YD) and β‐glucan content (BG). QTL analysis via stepwise regression detected a total of 33 QTLs, most of which were clustered in three linkage groups. Two dense linkage groups A1 and B13 were found to be putatively homologous to groups KO_6 and KO_11 of the ‘Kanota’/‘Ogle’ map, respectively.  相似文献   

5.
Since the release of the Chinese cabbage genome sequence, increasing interest has focused on the functional analysis of unidentified genes in Chinese cabbage. Mutant analysis forms the basis of functional genomics research. To produce a variety of Chinese cabbage mutants in the same genetic background, buds containing late uninucleate spores from a doubled haploid line of the Chinese cabbage variety ‘Fukuda 50’ were irradiated with 60Co γ‐rays at doses of 20, 40 and 60 Gy. Then, the treated microspores were isolated and cultured. A total of 492 putative M0 mutants were isolated from 1483 regenerated plants. Of these, six M1 mutants were verified; the mutant frequency was 0.41%. These mutants comprise a mutant library that includes one plant shape mutant, two flower mutants and three male sterile mutants. Pollen viability detection and DNA flow cytometry were used to determine the ploidy of the regenerated plants. Some of the mutants isolated in this study may be useful for Chinese cabbage breeding and functional genomics research.  相似文献   

6.
Historically, conventional breeding has been the primary strategy used to develop a number of Striga‐resistant varieties currently grown in the Sahel of Western Africa. In this study, we have successfully developed and applied a marker‐assisted selection strategy that employs a single backcross programme to introgress Striga resistance into farmer preferred varieties of cowpea for the Nigeria savannas. In this strategy, we have introduced the Striga resistance gene from the donor parent IT97K‐499‐35 into an elite farmer preferred cowpea cultivar ‘Borno Brown’. The selected 47 BC1F2 populations confirmed the recombinants with desirable progeny having Striga resistance gene(s). The 28 lines selected in the BC1F2:4 generation with large seed size, brown seed coat colour and carrying marker alleles were evaluated in the field for resistance to Striga resistance. This led to the selection of a number of desirable improved lines that were immune to Striga having local genetic background with higher yield than those of their parents and standard varieties.  相似文献   

7.
Vivek Maize Hybrid 9‐ a popular single‐cross hybrid developed by crossing CM 212 and CM 145 was released for commercial cultivation in India. The parental lines, being deficient in lysine and tryptophan, were selected for introgression of opaque‐2 allele using CML 180 and CML 170 as donor lines through marker‐assisted backcross breeding. The opaque‐2 homozygous recessive genotypes with >90% recovery of the recurrent parent genome were selected in BC2F2, and the seeds with <25% opaqueness in BC2F3 were forwarded for seed multiplication. Vivek Quality Protein Maize (QPM) 9, the improved QPM hybrid, showed 41% increase in tryptophan and 30% increase in lysine over the original hybrid. The grain yield of the improved hybrid was on par with the original hybrid. The newly improved QPM maize hybrid released in 2008 will help in reducing the protein malnutrition because its biological value is superior over the normal maize hybrids. This short duration QPM maize hybrid has been adopted in several hill states of North Western and North Eastern Himalayan regions.  相似文献   

8.
Grass pea (Lathyrus sativus L.) is an indeterminate grain legume considered adapted to dry environments, but the mechanisms of its adaptation are not well understood. Grass pea plants were exposed to terminal drought from podding, and the development of water deficit was measured together with its effects on leaf photosynthesis, stomatal conductance, carbon remobilisation to the seeds, flower production and abortion, pod production and abortion, seed set, seed growth and the neurotoxin β‐N‐oxalyl‐L‐a, β‐diaminopropionic acid (β‐ODAP) concentration. Predawn leaf water potential (Ψleaf), stomatal conductance (gs), rate of leaf photosynthesis (Pn), flower production, pod production, filled pod number, seed number, seed size and yield decreased, while flower abortion, pod abortion and seed abortion increased, and the concentration of β‐ODAP was unchanged under terminal drought conditions. gs and Pn began to decrease at a higher plant‐available soil water content (PAWC) (67.2 ± 2.3 % and 62.9 ± 2.3 %) than Ψleaf (43.7 ± 1.1 %). Flowers and pods ceased being produced only when the PAWC decreased below 40.1 ± 4.6 % and 35.3 ± 3.0 %, respectively, but seed set and seed growth ceased when PAWC decreased below 55.5 ± 1.6 % and 58.0 ± 3.7 %, respectively. The mobilization of 13C labelled assimilates from the stems was greater under terminal drought than under well‐watered conditions, but the transfer to the seed was small. We conclude that seed set and seed growth decreased as the soil dried due to a reduction in current photosynthesis as a result of stomatal closure.  相似文献   

9.
Rice stripe virus (RSV) predominantly affects rice. In this study, we attempted to localize the quantitative trait locus (QTL) conferring RSV resistance in the ‘Zenith’ variety, which is known to harbour Stv‐a and Stv‐b. The resistant variety Zenith was crossed with the susceptible variety ‘Ilpum’ to generate a mapping population comprising 180 F2:3 lines for QTL analysis. Contrary to previous findings, we could not detect Stv‐a‐specific QTLs on chromosome 6. Stv‐b‐specific QTL was detected on the long arm of chromosome 11; it was designated qSTV11z. Six F4:5 lines were selected from the F3:4 population and fine‐mapped using insertion/deletion (InDel) markers. qSTV11z was mapped to a 520‐kb region between the InDel markers Sid2 and Indel8. This region included OsSOT1 (candidate gene for STV11) and other previously reported RSV resistance QTLs. The OsSOT1 sequence in Ilpum and Zenith was identical to that of the susceptible variety ‘Koshihikari’, indicating that OsSOT1 is not the candidate gene of qSTV11z. The localization of qSTV11z should provide useful information for marker‐assisted selection and determination of genetic resources in rice breeding.  相似文献   

10.
In wheat, semidwarfism resulting from reduced height (Rht)‐B1b and Rht‐D1b was integral to the ‘green revolution’. The principal donors of these alleles are ‘Norin 10’, ‘Seu Seun 27’ and ‘Suwon 92’ that, according to historical records, inherited semidwarfism from the Japanese landrace ‘Daruma’. The objective of this study was to examine the origins of Rht‐B1b and Rht‐D1b by growing multiple seed bank sources of cultivars comprising the historical pedigrees of the principal donor lines and scoring Rht‐1 genotype and plant height. This revealed that ‘Norin 10’ and ‘Suwon 92’ sources contained Rht‐B1b and Rht‐D1b, but the ‘Seu Seun 27’ source did not contain a semidwarf allele. Neither Rht‐B1b nor Rht‐D1b could be definitively traced back to ‘Daruma’, and both ‘Daruma’ sources contained only Rht‐B1b. However, ‘Daruma’ remains the most likely donor of Rht‐B1b and Rht‐D1b. We suggest that the disparity between historical pedigrees and Rht‐1 genotypes occurs because the genetic make‐up of seed bank sources differs from that of the cultivars actually used in the pedigrees. Some evidence also suggests that an alternative Rht‐D1b donor may exist.  相似文献   

11.
Plant 14‐3‐3 proteins are involved in signal transduction pathways of nitrogen and carbohydrate metabolism. An Eg14‐3‐3 ω gene was isolated from the mesocarp of oil palm. The 1055‐bp cDNA had an open reading frame of 774 bp that encoded for 258 amino acids, and the cDNA had 113‐bp and 195‐bp 5′‐ and 3′‐untranslated regions, respectively. The calculated molecular weight was 28.06 kDa, with a pI of 5.04. The palm 14‐3‐3 showed closest identity to 14‐3‐3 proteins of the omega group. The entire sequence of Eg14‐3‐3 ω showed 83% identity with 14‐3‐3 protein isoform 16R from Solanum tuberosum. Phylogenetic analysis showed that the Eg14‐3‐3 isoform was within the omega (ω) subgroup and, thus, was designated Eg14‐3‐3 ω. The Eg14‐3‐3 ω expression patterns were strong in the mesocarp as compared to the root. When Eg14‐3‐3 ω cDNA was overexpressed in transgenic calli, there was higher accumulation of oil in the transgenic calli than in the controls. Therefore, Eg14‐3‐3 ω has potential for applications in the breeding of oil palms in the future.  相似文献   

12.
Interspecific hybrids between Trifolium uniflorum and cultivated white clover (Trifolium repens) have highly useful characteristics for temperate pastoral systems derived from both parent species. However, the early hybrids (F1 and BC1) also have unacceptably poor seed production for commerce. This study analysed the basis for the poor seed production and investigated breeding strategies for overcoming the problem. The BC1F1 generation produced lower‐than‐expected numbers of heads per plant and seeds per floret. Backcrossing of selected hybrids to white clover corrected these deficiencies and created new variation. Seed numbers were also returned to near target levels by recurrent selection within the BC1 generation. Thus, it was possible to retain a theoretical average of 25% of T. uniflorum genome and still achieve high seed production per plant. The BC1F2 and BC2F1 generations produced high seed numbers per plant, along with reasonable variation. Both of these second‐generation hybrid forms have high reproductive potential and should be the focus for the selection of the desired combinations of agronomic and seed production traits.  相似文献   

13.
Heterosis, or hybrid vigour, has been used to improve seed yield in several important crops for decades and it has potential applications in soybean. The discovery of over‐dominant quantitative trait loci (QTL) underlying yield‐related traits, such as seed weight, will facilitate hybrid soybean breeding via marker‐assisted selection. In this study, F2 and F2 : 3 populations derived from the crosses of ‘Jidou 12’ (Glycine max) × ‘ZYD2738’ (Glycine soja) and ‘Jidou 9’ (G. max) × ‘ZYD2738’ were used to identify over‐dominant QTL associated with seed weight. A total of seven QTL were identified. Among them, qSWT_13_1, mapped on chromosome 13 and linked with Satt114, showed an over‐dominant effect in two populations for two successive generations. This over‐dominant effect was further examined by six subpopulations derived from ‘Jidou12’ × ‘ZYD2738’. The seed weight for heterozygous individuals was 1.1‐ to 1.6‐fold higher than that of homozygous individuals among the six validation populations examined in different locations and years. Therefore, qSWT_13_1 may be a useful locus to improve the yield of hybrid soybean and to understand the molecular mechanism of heterosis in soybean.  相似文献   

14.
Sixteen‐hundred BC1 plants of a cross between an early blight (EB) susceptible tomato (Lycopersicon esculentum Mill.) breeding line (‘NC84173’ maternal and recurrent parent) and a resistant accession (‘PI126445’) of the tomato wild species Lycopersicon hirsutum Humb. and Bonpl. were grown in a field in 1998. This population was segregating (among other traits) for growth habit, self‐incompatibility and earliness in maturity. To eliminate confounding effects of these factors on disease evaluation and h2 estimation, plants that were self‐incompatible, indeterminate and/or late‐maturing were eliminated. The remaining plants (146), which were self‐compatible and determinate (sp./sp.) in growth habit, with early‐ to mid‐season maturity, were evaluated for EB resistance and self‐pollinated to produce BC1S1 seed. The 146 BC1S1 progeny families, consisting of 30 plants per family, were grown in a replicated field trial in 1999 and evaluated for EB resistance and plant maturity. For each of the 146 BC1 plants and corresponding BC1 families, the area under the disease progress curve (AUDPC) and final disease severity (final percentage defoliation) were determined and used to measure disease resistance. The distributions of the AUDPC and final percentage defoliation values in the BC1 and BC1S1 generations indicated that resistance from ‘PI126445’ was quantitative in nature. Estimates of h2 for EB resistance, computed by correlation between BC1S1 progeny family means and BC1 individual plant values, ranged from 0.69 to 0.70, indicating that EB resistance of ‘P1126445’ was heritable. Across BC1S1 families, a small, but significant, negative correlation (r = ‐0.26, P < 0.01) was observed between disease resistance and earliness in maturity. However, several BC1S1 families were identified with considerable EB resistance and reasonably early maturity. These families should be useful for the development of commercially acceptable EB‐resistant tomato lines.  相似文献   

15.
Waxy (Wx) protein is a key enzyme for synthesis of amylose in endosperm. Amylose content in wheat grain influences the quality of end‐use products. Seven alleles have been described at the Wx‐D1 locus, but only two of them (Wx‐D1b, Wx‐D1e) were genotyped with codominant markers. The waxy wheat line K107Wx1 developed by treating ‘Kanto 107’ seeds with ethyl methanesulphonate carries the Wx‐D1d allele. However, no molecular basis supports this nomenclature. In the present study, DNA sequence analysis confirmed that a single nucleotide polymorphism in the sixth exon of Wx‐D1 changed tryptophan at position 301 into a termination codon. Based on this sequence variation, a PCR‐based KASP marker was developed to detect this point mutation using 68 BC8F1 plants and 297 BC8F2 lines derived from the cross ‘Ningmai 14’*9/K107Wx1. Combined with codominant markers for the Wx‐A1 and Wx‐B1 alleles, waxy and non‐waxy near‐isogenic lines were distinguished. The KASP marker was efficient in identifying the mutant allele and can be used to transfer waxiness to elite lines.  相似文献   

16.
Non‐pungent bell pepper (Capsicum annuum L.) lacks the cytoplasmic male sterility (CMS) nuclear restorer allele, Rf, and CMS cannot be employed in its F1 hybrid seed production. To demonstrate that the genic male sterility (GMS) system in non‐pungent bell pepper can be converted to the CMS male sterility system, the conversion of GMS to CMS for non‐pungent bell pepper line GC3 was conducted by introgression of S‐type cytoplasm and the Rf allele from tropical pungent donors. After morphological traits were evaluated, two lines from BC1F1 containing S‐type cytoplasm and four lines from BC2F2 containing Rf allele, phenotypically similar to GC3, were obtained and could be employed as CMS male sterile lines and restorer lines for non‐pungent bell pepper. Four molecular markers potentially linked to traits of interest were also evaluated in BC1F1 and BC1F2 populations. This is the first time that GMS has been successfully converted to CMS in bell pepper, a significant contribution for bell pepper hybrid seed production.  相似文献   

17.
Cold tolerance is a complex trait, and QTL pyramiding is required for rice breeding. In this study, a total of seven QTLs for cold tolerance in the Japonica rice variety ‘Nipponbare’ were identified in an F2:3 population. A stably inherited major QTL, called qCTS11, was detected in the region adjacent to the centromere of chromosome 11. In a near‐isogenic line population, the QTL was further dissected into two linked loci, qCTS11.1 and qCTS11.2. Both of the homozygous alleles of qCTS11.1 and qCTS11.2 from ‘Nipponbare’ showed major positive effects on cold tolerance. Through pyramiding the linked QTLs in the cold‐sensitive Indica rice cultivar ‘93‐11’, we have developed a new elite, high‐yielding Indica variety with cold tolerance.  相似文献   

18.
Soybean mosaic virus (SMV) can cause serious yield losses in soybean. Soybean cultivar ‘RN‐9’ is resistant to 15 of 21 SMV strains. To well‐characterize this invaluable broad‐spectrum SMV‐resistance, populations (F1, F2 and F2:3) derived from resistant (R) × susceptible (S) and R × R crosses were tested for SMV‐SC18 resistance. Genetic analysis revealed that SC18 resistance in ‘RN‐9’ plus two elite SMV‐resistant genotypes (‘Qihuang No.1’ and ‘Kefeng No.1’) are controlled by independently single dominant genes. Linkage analysis showed that the resistance of ‘RN‐9’ to SMV strains SC10, SC14, SC15 and SC18 is controlled by more than one gene(s). Moreover, Rsc10‐r and Rsc18‐r were both positioned between the two simple sequence repeats markers Satt286 and Satt277, while Rsc14‐r was fine‐mapped in 136.8‐kb genomic region containing sixteen genes, flanked by BARCSOYSSR_06_0786 and BARCSOYSSR_06_0790 at genetic distances of 3.79 and 4.14 cM, respectively. Allelic sequence comparison showed that Cytochrome P450‐encoding genes (Glyma.06g176000 and Glyma.06g176100) likely confer the resistance to SC14 in ‘RN‐9’. Our results would facilitate the breeding of broad‐spectrum and durable SMV resistance in soybeans.  相似文献   

19.
Freely nodulating soybean genotypes vary in their phosphorus (P) uptake and P‐use efficiency (PUE) in low‐P soils. Understanding the genetic basis of these genotypes’ performance is essential for effective breeding. To study the inheritance of PUE, we conducted crosses using two high‐PUE genotypes, two moderate‐PUE genotypes and two inefficient‐PUE genotypes, and obtained F1, F2, BC1 and BC2 populations. The inheritance of PUE was evaluated using a randomized complete block design. A generation mean analysis of phenotypic data showed that PUE was heritable, with complex inheritance patterns and the presence of additive, dominance and epistatic gene effects. Seed P, shoot P, root P, P‐incorporation efficiency and PUE were largely quantitatively inherited traits. There were dominance, additive × additive and dominance × dominance gene effects on PUE, grain yield, shoot dry weight, 100‐seed weight, root dry weight and shoot dry matter per unit P for populations grown under low‐P conditions. Dominance effects were generally greater than additive effects on PUE‐related indices. These PUE indices can be used to select P‐efficient soybean genotypes from segregating populations.  相似文献   

20.
This study aimed at developing, characterizing and evaluating two maize phenotypic‐selected introgression libraries for a collection of dominant plant height (PHT)‐increasing alleles by introgressing donor chromosome segments (DCS) from Germplasm Enhancement of Maize (GEM) accessions into elite inbred lines: PHB47 and PHZ51. Different backcross generations (BC1‐BC4) were developed and the tallest 23 phenotype‐selected introgression families (PIFs) from each introgression library (PHB47 or PHZ51) were selected for single nucleotide polymorphism genotyping to localize DCS underlying PHT. The result shows that most PIFs carrying DCS were significantly (α = 0.01) taller than the respective recurrent parent. In addition, they contained larger donor genome proportions than expected in the absence of selection or random mating across all BC generations. The DCS were distributed over the whole genome, indicating a complex genetic nature underlying PHT. We conclude that our PIFs are enriched for favourable PHT‐increasing alleles. These two libraries offer opportunities for future PHT gene isolation and allele characterization and for breeding purposes, such as novel cultivars for biofuel production.  相似文献   

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