摘要:

AbstractAssociations of 23 quantitative traits and 10 genetic marker characters were examined in 63 chromosome‐doubled lines (DH‐lines) derived from the F1‐ generation of a cross between an old and a modern spring barley variety. One fourth of the marker × trait combinations showed significant associations. More than two thirds of these associations were to earliness (heading date). Earliness was found to be controlled by two loci: the previously knowneaklocus and a new locus designated Ea. It is concluded that the associations of quantitative traits with the earliness loci were caused by pleiotropy. Associations were found between two absolutely linked C‐bands on chromosome 3 and QTLs (quantitative trait loci) for lodging, straw diameter, and length of top internode of the straw. The three loci on chromosome 5, eak and the two linked powdery mildew loci,Mla9andMlk, were associated with a possible QTL for magnesium concentration in grain. Association to the C‐band on chromosome 6 suggests QTLs for TGW (thousand grain weight), straw diameter and magnesium concentration in grain. LocusEstlon chromosome 3 was not associated with any of the quantitat

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1991.tb00511.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractNew intergeneric hybrids were obtained betweenTriticum aestivumL. cv. Tukuho’ (2n = 6x = 42, AABBDD) andAgropyron fragile(Roth) Candargy PGR 8097 (2n = 4x = 28, PPPP) at a frequency of 1.06 %, through the use of direct embryo culture andin ovuloembryo culture. Such hybrids could be used to transfer barley yellow dwarf virus (BYDV) resistance and winterhardiness into bread wheat. The somatic chromosome number in all the hybrid plants was 2n = 5x = 35, as expected. Considerable variation in chromosome pairing was observed among the different hybrid plants. Average meiotic chromosome configuration at metaphase I was 17.29 Is + 6.57 rod Us + 1.97 ring Us + 0.18 III + 0.03 IV + 0.002 VI. The high level of chromosome pairing in some F1hybrids was attributed toPh‐suppressor gene(s) present in A.fragile. The hybrids could not be backcrossed to wheat, but amphiploid seeds have been obtained by colchicine treatm

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1991.tb00512.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractTwoTriticum monococcumaccessions were found to be highly resistant to the Russian wheat aphid. An attempt was made to transfer the resistance to common wheat through direct hybridization or by using bridge species. In each of the four crossing strategies tried, a gradual loss of resistance occurred as hybrids with higher ploidy levels were obtained. It appeared that the level of resistance observed was directly proportional to the ratio of theTriticum monococcumgenome relative to other genomes. This would indicate suppression of the resistance gene(s) by the added genomes or dilution of its product(s) by those of homoeoloci. The degree of protection afforded by the gene(s) at the hexaploid level may prove to be small. Plants suspected to be homozygous for the resistance gene(s) were identified; however, further backcrossing to common wheat will be required to improve their agronomic types and meiotic regularities.

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1991.tb00513.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractAn analysis of Spanish land races ofAvena sativafrom the Germplasm Bank of the I.N.I.A. was carried out using starch gel electrophoresis. Samples of 15 seedlings per accession were used for estimating the intra‐ and interpopulational genetic variability. Electrophoretic analyses were performed with crude extracts from 15 day‐old seedling leaflets by means of eight isozymatic systems representing a total of ten genetic loci. Two systems were mono‐morphic in all the accessions, while the other six showed polymorphism both within and between populations. Intrapopulational variability was particularly high in this collection, only 16 out of the 137 accessions being uniform for all the isozyme systems. Thus the material was shown to represent a high potential of genetic variability for breeding progr

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1991.tb00514.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractEstimates of N2fixation in segregating populations of bean plants based on15N‐isotope methods are technically demanding and expensive; therefore, indirect measures based on related traits including total seed N were used to select for improved N2fixation and yield. In 1985, six populations of F2‐derived F3families resulting from six parental lines crossed to a common tester were grown in field trials on a low‐N soil. In 1986, 25 selected half‐sib families and two populations of full‐sib F4families were grown under similar conditions. Parents and a non‐nodulating soybean line were included both years. Narrow sense (HNS) heritability estimates based on parent‐offspring regressions ranged from 0.57 for total seed N to 0.39 for shoot biomass in one population, but were near zero for all measured traits in a second population. Among the criteria used to identify parental lines with superior potential for producing progenies with high total seed N, testcross population means combined with estimates of realized heritability were the most reliable. Selection of the best F3families for total seed N resulted in F4families with increased total seed N and higher seed yields, while seed protein percentage was unchanged. When plants are grown on low‐N soils, selection for total seed N offers a useful alternative to selection for increased N2fixation based on15N‐isotopic or total‐

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1991.tb00515.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractTwo double‐cross populations were used to evaluate the efficiency of independent, alternate, and simultaneous selection practiced from the F2to F8for resistance to anthracnose and angular leaf spot of common bean (Phaseolus vulgarisL.). Seven resistant and high‐yielding lines were selected from each of the four environments used during this study. These lines and the seven parents involved in two populations were evaluated in an 8 × 8 lattice design with three replications in two cropping seasons. Pathogen inoculum was used to create the three test environments: anthracnose alone, angular leaf spot alone, and anthracnose and angular leaf spot together. All entries were also evaluated in a fourth, disease‐free environment. Selection for resistance to anthracnose and angular leaf spot was effective in both populations. Mean disease scores of all selected lines for anthracnose were lower than that of angular leaf spot irrespective of selection environment. Among the three stress environments, yields were higher in the anthracnose environment. However, lines selected alternately for anthracnose and angular leaf spot were usually higher yielding, and the highest yielding line in both populations originated from this selection environment. The mean yield of selected lines was higher and the highest yielding line originated from the population involving a parent (G 1805) belonging to the Mexican highland race ‘Jalisco’. Positive association existed between seed yield of protected and pathogen‐inoculated environments. No association was found between resistance to anthracnose and angul

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1991.tb00516.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractInterspecific hybridization between the grasspea,Lathyrus sativus, and 15 wild species in Section Lathyrus is reported. Only two species, L.amphicarposand L.ciceraproduced viable F1hybrids with low fertility when crossed with L.sativusas male parent. Crosses with six other species produced pods following pollination when L.sativuswas the male, but seedlings were inviable, seeds did not germinate or pods were empty or had totally shrivelled seeds. When L. sativus was the female parent, only one cross with L.gorgoniproduced an F1, but the seedling was inviable. The germplasm resources of the grasspea are identified, with L.amphicarposand L.ciceraplaced in the secondary gene pool and the other species in the tertiary gene pool. The definition of these germplasm resources is discussed in terms of grasspea improvement through plant breeding.

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1991.tb00517.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractHybrids of wheat (Triticum durum) × rye (Secale montanum) (2n = 21) were treated with a 0.06 % solution of colchicine. In the induction of fertile plants, fertile spikes, and seed‐set per spike, the root immersion technique was 21.7 %, 14.1 %, and 4.4 % respectively more effective than the use of the inverted vial. Colchicine solutions ranging in pH from 3.5 to 7.5 with the root immersion technique reached the highest frequencies of fertile (or partially fertile) hybrids (77.7 %), and fertile spikes (68.9 %) at a pH 5.5 used for the treatment, although the highest overall percentage of large Q seeds resulted from treatments at low pH (3.5). The overall mean frequency of induced fertile plants was six‐fold higher when treated in a growth chamber (19/15 °C day/night temperature and 18 h photoperiod) compared to treatments conducted in a greenhouse. The frequency of euploidy (2n = 42) was found to be highest in the large seed class and lowest, i.e. just about 50 %, in the class of small

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1991.tb00518.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractOutcrossing rates ofCuphea lanceolataAit., a new Dilseed crop, have not been estimated; however, this species is known to be insect‐pollinated, self‐compatible, and autosterile. We used five allozyme loci and the mixed mating model to estimate the outcrossing rates of experimental populations ofCuphea lanceolataAit. grown at Corvallis, Oregon in 1987 and 1988. Populations were grown using densities of one and 27 plants m−2. Multilocus out‐crossing rate estimates of populations grown at low and high density ranged from 0.61 to 0.85 and 0.93 to 0.94, respectively. Density caused differences may be caused by differences in pollinator movement. In open plantings, e.g., space‐plant nurseries, selfing rates are increased by increased within plant pollination by bumblebees, the primary pollinators of C.lanceolatain temperate zones. The movement of pollinators between plants is enforced in dense plantings. We found C. lanceolata is predominantly al‐logamous, but selfing rates as great as 39.0 % were observed among space‐plants; thus, the progeny of an open‐pollinated individual plant grown in this type of nursery is a mixed half‐sib and S1family. Maximum outcrossing can be achieved by usin

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1991.tb00519.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractCuphea viscosissimaJacq. is an herbaceous annual dicot indigenous to the U.S. This species is being developed as a new oilseed crop and commercial source of medium‐chain fatty acids (MCFAs). In this paper, the phenotypes and genetics of themcm‐1 andcpy‐1 mutations of C.viscosissimaare described. These mutations affect the percentages of fatty acids of seed storage lipids. They were induced by treating seeds with 0.04Methyl methanesulfonate for 5 h. Observed segregation ratios for these mutations were not significantly different from expected ratios for codominant genes. Themcm‐1mutation eliminates 95.0 % of wildtype MCFAs — caproic (C6: 0), caprylic (C8: 0), and capric (Cio: 0) acid percentages are decreased from 0.8 to 0.0 %, 20.7 to 0.5 %, and 68.6 to 6.7%, respectively. Thecpy‐1mutation decreases C6: 0 and C8: 0 from 0.9 to 0.0 % and 19.8 to 3.9 %, respectively, whereas it increases C12: 0 and C14: 0 from 2.2. to 14.3 % and 0.8 to 7.4 %, r

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1991.tb00520.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY