摘要:

AbstractResistance toPolymyxa betaewas studied inBetaspecies of the sectionProcumbentes, in hybrids ofB. vulgariswithB. procumbensorB. patellaris, and in monosomic additions of chromosomes ofB. procumbensinB. vulgaris. In all experimentsP. betaeinfested with beet necrotic yellow vein virus (BNYVV) was used. This virus causes rhizomania in sugar beet, and the effect of vector resistance was studied by measuring virus concentrations. Cystosori ofP. betaewere not found in the wild species and the hybrids. Virus concentrations in these plants were low, and in half the number of plants the virus could not be detected. Results of experiments with the monosomic additions indicate, that resistance toP. betaeinB. procumbensis located on chromosomes 4 and 8. Some cystosori were present in these addition types, while cystosori were abundantly present in other addition types and all sib‐plants. Virus concentrations in the addition types 4 and 8 were lower than in their sib‐plants, but in almost all plants the virus could be detected. A significant correlation (r = 0.91; P<0.05) between average numbers of cystosori and average virus concentrations was found when addition families of type 8 were tested together withB. procumbensandB. vulgariscv. ‘Re

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1992.tb00184.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

AbstractIn the high amylose starch mutant ‘Glacier AC38’, a single recessive gene designatedamo1is responsible for an amylose content of up to 45%. A rapid technique was established in order to evaluate the amylose/amylopectin ratio in half kernels. To localize this gene, crosses with multiple marker lines and trisormes were conducted. In addition, RFLP markers were used to determine their mapping distance toamo1. Two markers are located 2 cM and 7 cM, respectively, fromamo1on chromosome 5S (1HS). The relationship between thewxandamo1genes was also examined and the role of theamo1gene in starch synthesis is discus

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1992.tb00185.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

AbstractThe reaction of tritordeum and itsHordeum chilenseandTriticumspp. parents toSeptoria triticiwas studied in field and seedling experiments. All H. chilense lines were highly resistant to all the isolates and did not allow pycnidia development. The ‘durum wheat isolate’ developed pycnidia only on durum wheats. The ‘breed wheat isolate’ was very virulent on bread wheat but also on the wild tetra‐ploid wheats. The other two isolates were compatible with durum and bread wheat. All hexaploid tritordeums were highly resistant both in the field and the seedling experiments. Some octoploid tritordeums allowed pycnidial development, but at much lower levels than their wheat parent. Resistance in tritordeum was not associated with plant stature and only in octoploid tritordeum was association of resistance with late maturity

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1992.tb00186.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

AbstractFour hexaploid triticale lines were crossed as females with aT. monococcum×S. cerealeamphiploid (AmAmRR), with the aim of introducing the genetic material of diploid wheat. F1‐plants (AmABRR)were back‐crossed with a parental form of 6×‐triticale as male and progenies were subjected to four different types of pollination with the aim of finding the optimal one in respect to gradual stabilization of introgressive hexaploid karyotypes. Beginning with BC1‐plants, a strong tendency to decrease the somatic chromosome number was observed. In subsequent generations this was accompanied by the decrease of seed germination and plant fertility. Both of these characters showed statistically significant dependence on somatic chromosome number variation which was analyzed in BC1/F2and BC2populations. Based on spike fertility, an effective selection pressure was applied to restitute the hexaploid chromosome number. In the BC1/F4generation, the first morphologically uniform secondary hexaploid lines were selected. 11.4% of the lines showed a non‐waxy spike — a morphological marker transmitted from

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1992.tb00187.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

AbstractPrevious genetic studies on resistance to aflatoxin production in maize (Zea maysL.) only used a limited amount of germplasm. The objective of this study was to determine general (GCA) and specific combining abilities (SCA) for resistance to prehar‐vest aflatoxin accumulation in grain, utilizing A619Lfysyn, A632Lfysyn, B73Lfysyn, HyLfysyn, Mol7Lfysyn, Wf9Lfysyn, and 914Lfysyn. We evaluated 21 F1crosses (diallel) for aflatoxin accumulation in grain in three environments. Twenty‐one days after mid‐silk, ears were slash‐inoculated withAspergillus parasiticus(Speare). Samples were analyzed for aflatoxins BlB2, G1and G2. Significant differences for aflatoxin accumulation were detected among environments, with the environment that experienced drought stress showing the highest concentration for all four aflatoxins. The GCA and crosses mean squares were not significant for any aflatoxin and the SCA mean square was significant (P = 0.1) only for aflatoxin G2. Relatively small quantities of aflatoxin accumulation on, and nonsignificant differences among the 21 F1crosses might be indicative of their inherently high resistance levels. The SCA sums of squares constituted two thirds or more of crosses sums of squares, which indicated a preponderance of dominance and/or epistatic effects for aflatoxin accumulation. The HyLfysyn GCA effect tended to increase aflatoxin Bland Wf9Lfysyn tended to reduce aflatoxin accumulation as it showed a significant (P = 0.1), negative GCA effect for aflatoxin G1. The F1cross Wf9Lfysyn × 914Lfysyn showed significant, negative SCA effect for af‐latoxins B1 and G1, whereas A619 Lfy syn × 914 Lfy syn and Mo17 Lfy syn × Wf9 Lfy syn tended to increase one or more aflatoxins. For aflatoxin Br, a significant environments (E) × crosses (C) interaction was largely due to E × GCA interaction, which, in turn, was due to an interaction of the B73 Lfy syn GCA effect with E. This interaction effect tended to reduce aflatoxin BS. The E × C interaction for aflatoxin G2 was due to both E × GCA and E × SCA interactions. B73 Lfy syn GCA × E tended to reduce aflatoxin G, and Mo17 Lfy syn GCA × E tended to increase aflatoxin G. Additive genetic correlations based on GCA effects among the four aflatoxins were significant (0.76 to 0.96), except the correlation between aflatoxins B, and G2 (0.43), suggesting that, in general, increasing resistance to one toxin may lead to resistance to the

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1992.tb00188.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

AbstractTo resolve the problem of low and unstable yield in buckwheat under unsuitable environmental conditions, five varieties were grown and compared in summer and autumn. Vegetative and reproductive growth characteristics were investigated, and embryo development was observed with Nomarski's differential interference contrast (DIG) microscopy. In summer, under high temperatures and longer day‐length, autumn‐type varieties showed faster vegetative growth and later reproductive development as compared to summer‐types. In the autumn, with generally good climatic condition for buckwheat growth in southern part of Japan, the embryo sacs and zygotes of both types developed normally. At 3 days after pollination (DAP), the embryos reached the globular stage. In summer, however, mostly abnormal embryo sacs were observed 3 DAP, leading to incomplete development, failure of fertilization or abortion of embryo. The abnormal embryo sacs were classified into 6 types. Abnormality of either type occurred in 91—100 % of the tetraploids, which is higher than in the diploids (50—77 %). The present study, conducted to clarify the factors causing low seed set in buckwheat under summer conditions, provides detailed information for further breeding of environment‐tolerant buckwheat. Di‐ploid genotypes which are less sensitive to unfavourable conditions and, thus, show more efficient fertilization in summer, should be considered for use as breeding material

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1992.tb00189.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

AbstractA collection of 51 accessions ofPhaseolus vulgarisL. from N.W. of the Iberian Peninsula was evaluated for phenological, morphological, and agronomic characters for two years to study patterns of variation. Data were subjected to cluster analysis by variables choice, and six groups could be identified. These in turn corresponded to each previously described races ‘Nueva Granada’ and ‘Chile’ of South American origin, and races ‘Durango’ and ‘Mesoamerica’ of Middle American domestication center. Accessions falling in race ‘Nueva Granada’ had two

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1992.tb00190.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

AbstractTwo populations of common bean,Phaseolus vulgarisL., were used to make three independent location‐specific selections at Palmira, Quilichao, and Popayán, Colombia. Also, three across‐location selections were made by alternating generations between Palmira and Popayan, between Quilichao and Popayán, and among Palmira, Quilichao, and Popayán. The seven highest yielding lines selected from each environment and population along with 14 parents and two checks were evaluated for seed yield, seed weight, maturity, and reaction to an‐thracnose, angular leaf spot, and common bacterial blight. Mean squares due to evaluation and selection environments, selected lines, and their interactions were significant for all traits. Mean yields of selected lines were higher than the mean of parents in both populations. Among location‐specific selections, lines yielded higher at their respective selection site. Moreover, selections made at Popayán were higher yielding than those made at Quilichao or Palmira when tested across locations and years. Use of Popayán, a relatively wetter and cooler site, either alone or in combination with other locations resulted in higher yield, higher seed weight, and higher resistance to anthracnose. On the average, location‐specific selections were lower yielding than the across‐location selections. Among across‐location selections, those selected between Palmira and Popayán were the highest yielding in both populations. Selections at Palmira and across all three locations resulted i

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1992.tb00191.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

AbstractThe abundant lectin phytohemagglutinin (10 % of total seed protein) does not contain sulfur amino acids and, being a potent antimetabolite, it is responsible for the lowering of the nutritional value of bean seeds. The aim of the present work was to improve the dry bean cultivar ‘Taylor's Horticultural’ (Asgrow), by genetically introducing the lectin null (lec/lec) character from two null genotypes: ‘Pinto UI 111’ and ‘Heidi’. Thirty‐seven BC2F3and fourteen BC6F5inbred lines were evaluated in agronomical trials. Analysis of Variance (ANOVA) showed significant differences among BC2F3breedings lines for all traits under evaluation. Comparison of the LedLee genotypes versuslec/lecdid not show statistically significant differences in the means for the following traits: yield, yield components and percentage of protein in the seed. Fourteen BC6F5 lines, compared together with their recurrent parent ‘Taylor's Horticultural’, showed significant differences among genotypes for 1000 seed weight, protein percentage on dry matter and ash percentage. No significant differences were observed for grain yield. The data indicate that lectin removal did not have a detrimental effect on the

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1992.tb00192.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

AbstractRFLP markers which were previously assigned to chromosome 2 (2H) were found to detect polymorphism between the cv. ‘Pallas’ and a near isogenic line carrying theLaevigatumresistance geneMlLa.Linkage analysis carried out with two sets of DH lines derived from the crosses ‘RisøS’בSultan’ and ‘Alf’בVogelsanger Gold 2’ confirmed three DNA probes closely li

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1992.tb00193.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY