摘要:

AbstractSeedlings of 26 wheat caltivars from Pakistan were tested with 18 British races ofP. striiformis.It is postulated that the race‐specific genesYr6, Yr7, Yr9and perhapsYr2were present among the cultivars, and that there was other resistance not controlled by these gene

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1986.tb01069.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractThe aim of this study was to delta differences in resistance to the carmine spider mite, Tetranychus cinnabarinus between cotton varieties grown in different areas. The effects of 8 varieties from several countries cm the development, longevity and fecundity ofT‐cinnabarinuswere investigated in the laboratory. On leaves of the Egyptian cotton,Gossypium vitifolium, variety Giza 75, both females and males required a longer period to complete development than on the G.hirsutumvarieties Coker 310 and MCH H. Female mites reared on the variety Coker 310 lived significantly longer and had the longest oviposition period. The largest total progeny per female was observed on the varieties Coker 310 and MCH H, the smallest on the varieties Aleppo 1 and Giza 75. The cotton varieties had no effect on the sex ratio ofT. cinnabarinus.In general, theG. hirsutumvarieties Coker 310 and MCH 11 appeared to be most supportive forT. cinnabarinus, whereas theG. vitifoliumvariety Giza 75 clearly showed reduced susceptibilit

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1986.tb01070.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractWith the aim to transferPhoma lingamresistance into rape, successful interspecific crosses were made between three oilseed rape varieties (Brassica napus) and the resistant speciesB. carinataandB. carinata.Although both hybrid typesB. napus×B. junceaandB. napus×B. carinatashowed the same high level of resistance as the respective resistant parent, the resistance could be only transferred fromjunceacrosses. After three backcross generations, lines morphologically undistinguishable from rape, fertile, and with a high degree of resistance were obtained. The resistance ofB. carinatawas practically lost in the first backcross. A possible explanation of this different behavior could be a higher recombination between the genomes B and C (junceacrosses) than between B and A (carinatacrosses). The: applied embryo culture increased the yield of hybrids and first backcross plants and reduced considerably the generation tim

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1986.tb01071.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractCrosses were performed between ninePhaseolus vulgarislines (as females) and sevenP. acutifoliuslines (as‐ male to examine parental compatibility for the production of vigorous hybrid And backcross plants,in vitroembryo rescue techniques were required to secure hybrid and backcross proseny following interspecific crossing. Seedling development appeared to be dependent on which allele theP. vulgarisparent carried at an interspecific incompatibility locus. Seven of the nineP. vulgarislines tested carried an allele at this locus which interacted with a nuclear factor in theP. acutifoliusgenome resulting in stunted, sub‐lethal hybrids. The lines, ICA pijao' and ‘Sacramento Light Red Kidney’ did not carry this allele and produced vigorous hybrid progeny in combination with allP. acutifoliusparents. Intensive backcrossing produced progeny which also segregated for sub‐lethal and viable plant development. The observed segregation patterns suggest that a bridge crossing scheme would facilitate the introgression ofP. acutifoliusgermplasm into incompatibleP. vulgarislines. Similarities, with an intraspecific incompatibility system are

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1986.tb01072.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractSeveralNicotianaspecies, their intergeneric sexual and somatic hybrids were compared for theirin vitrogrowth rate and nicotine content. Cell yield on a dry weight basis and HPLC analysis of their nicotine content revealed a very high variation within each cell line from parental, sexual and somatic hybrids for the two traits analyzed. The trigeneríc sexual hybrids(N. rustica × N. debneyi) × N. tabacumand only two of the N. rustica × N. tabacum somatic hybrid lines show a positive heterosis in nicotine contentin vitroThein vitrogrowth rate and nicotine content did not demonstrate a statistically significant correlat

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1986.tb01073.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractThe absorption of Mo by the roots and. transport to the shoot of intact seedlings of a sorghum hybrid and its parent cultivars were measured for 3 h from 10 to 100 μmol ammonium molybdate. The patterns of absorption revealed hybrid vigour and the hybrid followed the patterns of the male‐ parent 168. Studies on the effects of different amounts of Mo on the nitrate reductase activity also showed the occurrence of hybrid vigour in the‐ hybrid C

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1986.tb01074.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractDevelopment of tall fescue (Festuca arundinaceaSchreb., 2n = 6x ‐ 42) × Italian rye‐grass (Lolium multiflorumLam., 2n = 2 ×= 14) hybrids would enhance efforts to improve the quality of tall fescue. Two ‘Kentucky 31’ tall fescue בLemtal Italian ryegrass hybrids were obtained via embryo rescue on MS media containing casein hydrolysate, ascorbic acid and sucrose. Chromosome pairing at metaphase I had an average of more than 12 bivalents per cell. SinceFestuca‐Loliumpairing can account only for seven of the paired chromosomes, intergenomic as well as interspecific chromosome pairing is indicated. There was no cytoplasmic effect on chromosome pairing.To determine if enzymes could be used as genetic markers for distinguishing hybrids from self‐contaminants in crosses, zymograms of PGI, 6‐PGD, MDH, GOT and ACPH were obtained from parents and hybrids using starch gel etectrophoresis. PGI, 6‐PGD and MDH had fewer bands in the diploid ryegrass, as compared with the hexaploid tall fescue and t

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1986.tb01075.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractDivergent selection for heading time was performed in two F2barley population. Five populations were obtained for each cross: F5SSD (unselected control), 3E and 3L (from three cycles of selection for earliness or lateness), 2E1L and ZL1E (from two cycles of direct and one of reverse selection). These populations, together with corresponding parents and F2generations, were evaluated over two years. The response to selection was 5.6 and 6.5 days inane direction (earlier heading) and 7.7 and 6.7 clays in the other direction (later heading) in the two crosses, respectively. 3E and 3L populations were highly transgressive as compared to their parents. A sizeable amount of genetic variability was still present after two cycles of selection. Heading was probably controlled by a polygenic system with prevailing additive effects and alleles for earliness and earliness somewhat equally distributed in the parents. Selection fur heading time led to significant changes in plant height, yield and kernel weight. Early progenies were higher yielding than lace ones.

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1986.tb01076.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractDry seeds of an early variety of jute (Fanduk) were X‐irradiated to study the effect of selection for days to flower. Variation was induced in days to flower as evident from the high values of genotypic variances and hen lability estimates in the Mi generation. Asymmetric‐response was realized in the M4 generation following disruptive selection — response being more towards lateness than earliness. However, significant variances for days to flower were present among both early and late selections in M4 generation. While late lines were superior to the mother variety in plant height and fibre vie Id: pi ant, early lines were inferior to the mother variety in these‐traits. Distribution of 15 late lines in fibre yield and plant height classes showed that S lines exceeded the mother variety in fibre yield, plant and 7 of them exceeded it in plant height. In general, gradual shift towards lateness was associated with gradual shift towards greater plant height and fibre yield. Two late lines were very promising and earlier in maturity than the recommended early va

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1986.tb01077.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractThe components of genetic variation were studied in four F2crosses (PG3× 5064, T163× B.V., T163× Arkel and 5064 × ED) for quantitative characters such as days to flowering, plant height, pod number, seed number, test weight and yield/plant. The overall epistasis (T type) was, in general, a major contributor for genetically controlling the expression of the characters in all the‐ four crosses except for the character seed number in crosses 1 and JV, where the j + l component at epistasis played a significant role in determining the expression of this attribute:. Though the ‘j + l’ component of the epistasis was significant, it was relatively less important than the ‘i’ type epistasis. Both the additive and dominance components of the genetic variation were highly significant for all the trans studied in all die four sets of crosses. The expression of the dominance was directional only for a few characters in certain crosses. The degree of dominance lies in the partial range, and heritability estimates obtained were high for most of the trails. The possible application of cross prediction in the isolation of superior recombinant inbred lines in pea

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1986.tb01078.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY