摘要:

AbstractMale fertility of F1interspecific hybrid plants derived from crosses between cytoplasmic male‐sterileBrassica campestrisinDiplotaxis muraliscytoplasm and 147B. napuscultivars was Investigated. F1, plants obtained, from crosses with the B. napus cultivars‘Mangum’and‘Hinchu’were male‐sterile while F1plants derived from all other crosses were male‐fertile. This indicated that these two cultivars carried maintainer genes far the male‐sterility‐inducing cytoplasm ofD. muralis.Sterility was stable In plants derived from backcrosses of male‐sterile F; plants with‘Mangun and‘Hinchu’but the seed set of backcross plants was low. With restorer genes readily available inB. napus, these findings could lead to the development of a new cytoplasmic male sterility system for the breeding o

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1987.tb01157.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractIn the study of interspecific and interploidy hybrids ofAvenathe order of spikelet types in the recessive

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1987.tb01158.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractEarly generation yield trials of families from a set of winter wheat crosses were grown in three contrasting environments chosen to represent differences in two important macro‐environmental variables affecting the wheat, crop in Eastern England. Joint selection for high yield and low sensitivity to these macro‐environmental variables over two seasons using the procedure of Brumptonet al. (1977) resulted in a group of genotypes which exhibited a much wider yield range than would have resulted from selecting for yield in each ‐environment separately. In spite of this, the top performing lines an yield trials grown in each of the environments during the next season exhibited good yield and stability over all three environments, demonstrating the feasibility of such a method for winter wheat bre

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1987.tb01159.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractTwo sets of accessions were sampled, tram a natural population ofHordeum spontaneumat Shelomi, Israel, viz.: 100 ears along a transect at intervals of 1—1.5 m and 10 ring clusters of 10 ears each, circling each 10th plant of the transect. Single ear progenies were tested for banding patterns of 5 allozyme loci; in addition, hordein sanding; and field reaction against powdery mildew has been determined. 56 allozyme genotypes and 13 hordein patterns were determined. Most of the progenies showed susceptible to moderately susceptible infection types and high frequencies of low infection grade (slow mildewing). For all characters spatial grouping was found in plants derived from neighbouring transect parents. This was even more pronounced in the ring clusters. Reactions to mildew infection appeared to be closely correlated with hordein banding. In addition, accessions showing hypersensitive reactions carried excessive frequencies of a certain allele of theEst‐1lo

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1987.tb01160.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractIn cowpea, black seeded types are supposedly resistant toMacrophomina.A study was undertaken to verify the association of seed colour with resistance toMacrophominaandXanthomonasand to examine the response over three cycles of selection for such resistance along with seed yield, determinate habit and synchronous flowering in five black‐and three white‐seeded cowpea varieties. Selection was done between and within progenies under heavy natural incidence of both pathogens supplemented by artificial inoculation ofMacrophominausing the toothpick method at flower primordial stage. Among 414 single plant progenies in the first cycle all 193 white‐seeded progenies from three different varieties were highly susceptible to both pathogens, with considerable variation among the black‐seeded ones. All the black‐ and white‐seeded progenies derived from the same variety‘Floricream’were highly susceptible. Multivariate analysis for five characters in the ten best progenies after two selection cycles revealed significant genetic diversity between the progenies. Selection was successful with the isolation of three productive progenies resistant: to both diseases. The results indicated that seed colour had no influence on resistance m this material and that simultaneous improvement of seed yield, plant type and disease resistance co

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1987.tb01161.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractThe genetics of resistance of common vetch (Vicia sativaL.) to broomrape (Orobanche crenataForsk.) was studied for two years by using the P1, P2, F1, BC1, BC2, F2F3, and F4generations obtained from crosses between resistant and susceptible lines. Resistant lines were selected by screening a world collection m a naturally infested plot. Resistance was tested both under field and greenhouse conditions. The best index to measure resistance was the number of emerged broomrapes per host plant. The results fit the additive‐dominance model. The main component of the variation was additivity; dominance and interaction effects seemed to depend on the environment. When dominance is expressed, a low number is dominant over a high number of broomrapes per host plan

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1987.tb01162.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractMeiotic observations of 56‐chromosome plants of the C1, C2and C3generations of the amphidiploidLolium multiflorum × Festuca arundinaceashowed that most of the chromosomes paired as bivalents. However, uni‐ and multivalents were frequently observed. No difference in meiotic regularity and stability could be detected between the different generations. The average chromosome number and; the percentage of 56‐chromosome plants decreased with increasing generations. The direct use of the 56‐chromosome amphidiploids ofL. multiflorumandF. arundinaceain a breeding programme appears to be quite difficult, but these plants can be used in a backcross programme withLoliuman

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1987.tb01163.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractBasal leaf sections ofTriticum aestivumL., cv. ‘Chinese Spring’, and XTriticosecaleWittmack cv.‘Welsh’were cultured on Kao's medium with 2 mg/l of 2,4‐D. Callus was induced on the leaf sections at frequencies of 64 and 63 %, respectively, and plant‐lets regenerated at 18 and 31 %, respectively. Compared to the controls, the regenerated plants showed higher frequencies of univalent chromosomes at meiosis and low frequencies of trivalents, and quadrivalents; indicating that the callus phase had induced low frequencies of chromosome i

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1987.tb01164.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractThe diploid hybridHordeum californicum×Secale vaviloviiand the tetraploid hybrid H.parodii× S.anatolicum, were obtained through embryo rescue techniques at relative frequencies of 0.70 and 5.3 % of pollinated florets, respectively. Means of 11.741+ 1.1311per cell at metaphase I of meiosis were obtained in the diploid hybrid and 14.741+ 6.3l11+ 0.22111+ 0.02IVin the tetraploid hybrid with a maximum of 6.01+ 4.011and 9.011+2.0111+ 1.0IVrespectively. In the diploid hybrid there was preponderance of intragenomic pairing (86.7 %). Increased pairing in the tetraploid hybrid was attributed to autosyndesis amongHordeum chromosome

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1987.tb01165.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractCalli of two genotypes of barley,‘Dissa’and W 193, were used for selection of resistance against fusaric acid, a pathotoxin ofFusarium.Callus was initiated from 7‐ to 10 days old immature embryos. 1000 calli of the‘Dissa’and 500 of the W 193 genotypes were grown for 4 selection cycles on medium with 0.8 mM fusaric acid. In the first selection cycle, about 80 % of the calli were killed; after the 4 selection cycles, 8 to 11 % resistant calli were obtained and plants were regenerated. Resistant calli maintained on non‐toxic medium showed retention of resistance ability after 3 months of sub‐culturing. Plants could be regenerated from the surviving calli and testing by leaf bioassay revealed that many were resistant to the same toxin concentration employed for callus selection (100 %), while some were only resistant up to a concentr

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1987.tb01166.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY