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991.
抗旱、耐盐碱、矮秆陆地棉数量性状的遗传相关及主成份分析 总被引:4,自引:1,他引:4
对从国内外引进的抗旱、耐盐碱、矮杆棉花资源材料 ,经抗旱、耐盐碱、矮杆性鉴定和比较 ,选取了其中表现较好的 1 9份材料 ,进行了遗传相关和主成份分析 ,结果表明 :在 5 0 mmol· L- 1Na Cland1 0 0 mmol· L- 1Na Cl胁迫下的出苗率间呈正相关 ,抗盐性与产量间呈负相关 ;第一棉铃高度与纤维品质性状呈正相关。抗旱、耐盐碱、矮杆棉花材料的前 6个因子贡献率达 86.5 % ,其分别为第一棉铃高度因子、果枝数因子、单株结铃数因子、矮杆因子、单铃重因子等 相似文献
992.
993.
Osmotic adjustment (OA) is considered as an important physiological mechanism of drought adaptation in many crop plants. The present investigation was aimed at assessing the importance of OA in improving productivity under drought. Using two automated rain-out shelters, 26 extra-short-duration pigeonpea [Cajanus cajan (L.) Millsp.] genotypes were grown with irrigation during the growth period or with water deficit imposed from flowering until maturity. Mean leaf Ψs100 (60–92 DAS) under drought correlated significantly (r2=0.72**; n=26) to the mean OA (60–92 DAS) and contributed 72% of the genotypic variation in OA. Significant genotypic variation was observed in the initiation of OA, the duration of OA and the degree of OA. Based on the measured OA at 72, 82, and 92 days after sowing (DAS), genotypes were grouped into five different clusters. Genotypic differences in total dry matter production under drought were positively associated with OA at 72 DAS (r2=0.36**, n=26). Significant positive relationship between OA at 72 DAS and grain yield under drought was found (r2=0.16*; n=26). However, OA towards the end of pod filling phase, i.e. at 92 DAS, had a significant negative relationship with grain yield under drought (r2=0.21*; n=26). Genotypic differences in grain yield under drought was best explained using stepwise multiple regression to account for differences in OA at 72, 82, and 92 DAS (r2=0.41**; n=78). The degree of OA at 72 and 82 DAS contributed positively to the grain yield, whereas OA at 92 DAS contributed negatively to this relationship. 相似文献
994.
Sijun Zheng Betty Henken Willem Wietsma Eri Sofiari Evert Jacobsen Frans A. Krens Chris Kik 《Euphytica》2000,114(1):77-85
The beet armyworm (Spodoptera exigua Hübner)is the most important pest in tropical Alliumcultivations. All shallot (Allium cepa L. group Aggregatum) cultivars are susceptible to this pest. Therefore accessions from three wild Alliumspecies, namely A. galanthum Kar. et Kir., A. fistulosum L. and A. royleiStearn, next to A. cepa L. were used to screen for resistance. First of all, a reliable bio-assay had to be developed. To this end transparent plastic
cages with in total 5 plants of one accession per cage were placed on per lite in a heated greenhouse. Five 3-day old larvae
were inoculated on each plant. Eight days after inoculation the number of surviving larvae per cage and the mean fresh weightper
larva was determined. The lowest larval survival (36%) was found on A. roylei. This was not, however, significantly different from other Allium accessions. Significant differences were found in the fresh weight per larva fed on different Allium accessions. The larvae survived on A. roylei had a very low fresh weight (10.3 mg per larva), while those on an accession of A. fistulosum had the highest fresh weight (45.1 mg per larva). The larval fresh weight on A. roylei was lower than all the other accessions except from the tropical shallot cultivar Bawang Bali. To check whether or not a
toxic compound was involved in the resistance present in A. roylei, tenaccessions from four Allium species were screened. Five 3-day old larvae were inoculated on regularly replaced leaf material of each accession ofAllium species. No significant differences were found in mean fresh weight per larva and mean survival of larvae among different
accessions. There were also no significant differences in pupal weight and developmental time. All larvae became pupae 10
days after inoculation. The data indicate that there is no toxic compound present in A. roylei. These results are underlined by the observation in the greenhouse bio-assay that A. roylei plants were equally damaged by the beet armyworm compared to otherAllium species. The results obtained so far therefore suggest that introduction of resistance to S. exigua via the exploitation of variation for resistance to the beet armyworm in A. roylei is unclear and that genetic engineering using Cry sequences could provide a way forward.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
995.
RAPD (randomly amplified polymorphic DNA) analyses were carried out on 21 accessions of Lachenalia bulbifera (Cyrillo) Engl. Five pre-selected primers produced an average of 88% polymorphisms. Fifteen of the 21 accessions could be
identified using the five primers. In a pairwise comparison genetic distance values ranging from 0.11 to 1.08 were obtained.
These values reveal a high amount of variation within the species. The genetic distance values within the tetraploid and hexaploid
groups on the south coast were low, but values were high between the groups on the south coast and those on the west coast.
A dendogram was constructed from the RAPD banding profiles, using UPGM cluster analysis. The dendogram clusters certain accessions
together. These clusters are supported by their geographical locality and chromosome data. The hexaploid group, tetraploid
group and octoploid group on the south coast are respectively clustered together. It is concluded that RAPDs can be used to
assess the genetic variation at an intra-specific level in Lachenalia.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
996.
Successful selection of interspecific hybrid progenies with superior ability to regenerate shoots from apical meristems was
performed in sunflower which now allows for the development of lines for improved biotechnological applications. Early generations
of interspecific hybrids originating from crosses between the two H. annuus CMS lines ‘HA89’ and ‘Baso’, and 9 wild species were screened for their ability to regenerate in vitro. Evaluation of 36 progenies allowed to identify seven progenies from crosses involving H. mollis, H. giganteus, H. strumosus, and H. decapetalus which showed a significantly higher regeneration potential than the commercial hybrid ‘Albena’ regarding the number of shoots
per explant. Among these progenies, 47.2 to 62.4% of explants produced shoots with an average of 2.3 to 3.5 shoots per cultured
explant. Regeneration in vitro was significantly determined by the genotype. More than half of the investigated interspecific hybrids performed better than
the inbred ‘HA89’ demonstrating that the high regeneration potential available in the wild species can be efficiently transferred
to cultivated sunflower. The seven progenies with high regeneration potential in vitro were characterised by agronomic performance in the field. Two of the interspecific hybrids derived from H. strumosus and H. decapetalus not only showed a superior regeneration potential but also proved to be competitive to commercial hybrids with regard to
important agronomic traits, e.g. fat content and TGW.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
997.
Noel E.A. Murphy Robert Loughman Robin Wilson Evans S. Lagudah Rudi Appels Michael G.K. Jones 《Euphytica》2000,113(3):227-231
Septoria nodorum blotch is the most important leaf disease of wheat in Western Australia. A potentially useful source of resistance
has been identified in an accession of Aegilops tauschii. To study the genetics of resistance of this source a cross was made between the resistant Ae. tauschii accession, RL5271, and a susceptible accession, CPI110889. The resistant parent took significantly longer to develop symptoms,
developed significantly fewer lesions and expressed significantly lower levels of disease than the susceptible parent. The
F1 mean response for disease severity indicated there was no complete dominance. The F3 families were classified using three
approaches. In the first approach the individual F3 plant response was used to classify the F3 families. In the second approach
the F3 family means and standard errors were used to classify the F3 families. In the final approach Best Linear Unbiased
Predictors of disease score and standard error for each F3 family derived from a REML analysis were used to classify the F3
families. The genotypic ratios generated by each of the approaches suggested that resistance is controlled by a single gene.
The effectiveness of the resistance and its simple genetic control in the Ae. tauschii, accession RL5271 may be a useful resistance source for use in a bread wheat breeding program.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
998.
Chromosomal localization of five mutant genes in rice, Oryza sativa, using primary trisomics 总被引:4,自引:0,他引:4
The chromosomal locations of five mutant genes in rice were determined by crossing the marker stocks with the 12 primary trisomics. Genetic segregation of each gene was studied in the F2 or backcross populations. Out of the 60 possible cross combinations, 43 F2 or BC1 populations were studied. Segregation data indicated that spl11 was located on chromosome 12 while wp2 and eg2(t) were located on chromosome 6. The genes v12(t) and Bc6 were located on chromosomes 8 and 9, respectively, which are sparsely populated with genetic markers. 相似文献
999.
Linkage analysis of RFLP markers for clubroot resistance and pigmentation in Chinese cabbage (Brassica rapa ssp. pekinensis) 总被引:15,自引:0,他引:15
A restriction fragment length polymorphism (RFLP) – based linkage map of Chinese cabbage (Brassica rapa ssp. pekinensis) (2n=20)
including two agronomic traits, clubroot resistance and orange-yellow pigmentation, was constructed using doubled haploid
parents. The total linkage distance was 735 cM; 63 loci were distributed into ten linkage groups. Clubroot resistance of the
parental line T136-8 to the current pathotype, race 2, was predominantly controlled by a single dominant gene that originated
from European turnip. The locus for clubroot resistance by the dominant major gene (CRa) was mapped on linkage group 3, and
RFLP loci HC352b and HC181 were located 3 cM and 12 cM from it, respectively. The locus HC352b was identified by a 4.4 Kb
Eco R I fragment, which segregated for null allele. The absence of an allelic fragment in HC352b could be interpreted by deletion
in the resistance source; homozygotes for CRa could be efficiently selected by detecting null types for the marker. Orange-yellow
pigmentation expressed in head inner leaves and petals was governed by a single recessive gene. The locus (Oy) for the pigmentation
was mapped on linkage group 1, being located 17–19 cM from three RFLP loci that were closely linked to each other. The linkage
analysis for clubroot resistance and unique pigmentation revealed some informative RFLP markers. Identification of molecular
markers for clubroot resistance and other agronomically important traits would provide useful information in breeding programs
of Chinese cabbage.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
1000.
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