摘要:

AbstractThe study was designed to provide information on the inheritance of the fruiting period in strawberries and to ascertain whether pistillate seedlings differed in any important respects from their hermaphrodite sibs. Seven short‐day genotypes, covering the full range of outdour cropping seasons in the UK, were crossed in a half‐diallel without selfs and the seedlings grown in the field. Six plant characters, components of fruiting season, yield and vigour, were analysed and each one was found to be heritable with the additive genetic component contributing more towards the overall genetic variance than the non‐additive component. There was more variation for flowering time than for maturation time but both characters are important when breeding for an extended season.The pistillate cultivar‘Pandora’ contributed both the latest flowering and slowest fruit maturation to its progeny and an association was found between late flowering and pistillate flowers, suggesting a possible linkage. This will limit the usefulness of‘Pandora’ as a parent when breeding late‐fruiti

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1992.tb00170.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

AbstractIn genotype‐environment interaction studies, in long‐term multi‐site trials, two main problems arise: missing values, and assessment of environments which consist of diverse locations and years. In this paper, a factorial regression model on asparagus data has been used to overcome these difficulties. These data consist in yields of seven asparagus standard varieties observed in 35 combinations of 4 locations × 9 years with missing values. Two kinds of covariates were kept in the model: (i) a biological one, ej, which is the main environmental effect estimated with the additive model on a chosen set of genotypes (standard varieties); and (ii) three external environment covariates: the latitude of the location, the type of production (green or white asparagus), and the mean temperature during the five months preceding the beginning of the harvest. These results suggest that a significant part of genotype × environment interaction in asparagus is due to the different effects of low temperature during the dormant period on the physiology of the sub‐ground crown, depending on the

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1992.tb00171.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

AbstractThe steroid bearing medicinal plant,S. laciniatum, was bred for high solasodine yield for commercial cultivation in Thailand.Starting materials for breeding consisted of seven populations of different origin. Variability among these populations was examined using an unselected control population cultivated over three years. Additive and dominance variance were estimated from a polycross and diallel mating design.Significant genotypic variability was found for solasodine concentration, height of the plants, and total shoot length, promising successful selection for the most important yield characters.Additive variance and heritability in the narrow sense were low for all yield characters, due to previous selection of the parental plants used for the polycross and diallel mating.No dominance effects could be found for any of the characters. In conclusion, breedingS. laciniatumfor quantitative yield characters by selection will be superior to hybrid breeding.As a result of selection, significant increases in the most important yield characters in the offspring of selected populations were obtained.

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1992.tb00172.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

AbstractNew crop development often depends on a few essential traits such as nonshattering of seed at maturity and pollination control. In order to domesticateLimnanthes alba(meadowfoam), as a source of industrial oil, we performed genetic analysis of crosses betweenL. albaand its closest relativeLimnanthes gracilisvar.graciliswhich shows higher selfing ability and nutlet abscission. Differences in pubescence, nutlet abscission, and seedling pigmentation were each found to be governed primarily by a single locus; two interacting loci appeared to control capsule dehiscence. Segregation distortion was detected for pigmentation in F2and F3populations, and for pubescence in several F3families. Loci controlling pubescence, nutlet abscission, and capsule dehiscence resided in a single linkage block which assorted independently of the locus controlling pigmentation.

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1992.tb00173.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

AbstractThe use of hexaploid triticale as a crop for human consumption has been limited by its inferior bread‐making quality. To ameliorate this problem, a segment of chromosome ID of breadwheat with theGlu‐D1dallele encoding for high molecular weight glutenin subunits 5 7plus; 10 was translocated to chromosome 1R of the hexaploid triticale ‘Rhino’ through a combination of a centric break‐fusion translocation followed by 5D(5B)‐induced homoeologous pairing. The resulting recombinant chromosome 1R has a small interstitial segment of ID with theGlu‐D1dallele. The maximum physical length of the translocated segment is estimated at about 16.5 % of 1DL. Frequency of translocations involving the long arms of homoeologous group‐1 chromosomes in the analyzed progeny suggested that homoeologous recombination in triticale was substantially higher than that previously reported in

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1992.tb00174.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

AbstractThis study was conducted to determine whether inexpensive starches and various agars could replace Ficoll, which is very expensive, and Bacto‐agar, which may be inhibitory, in wheat (Triticum aestivumL.) anther and immature embryo culture. Anthers from Pavon 76’ had significantly greater embryoid‐initiation frequencies (number of embryoids per anther) on PI media with corn (0.67) and wheat starch (1.50) than with Ficoll (0.47). Anthers on 85D12 media with Ficoll, corn starch and wheat starch had similar embryoid‐initiation frequencies (0.51, 0.50, and 0.52, respectively). The embryoid‐regeneration frequencies (number of regenerating embryoids per embryoid plated) on 85D12 media containing corn (0.32) and wheat (0.36) starch were significantly higher than on 85D12 with Bacto‐agar (0.14). Embryoids on MS media with Bacto‐agar, corn starch, and wheat starch had similar embryoid‐regenerating frequencies (0.15, 0.20, 0.22, respectively), which were greater than with some of the other agars tested (0.05 to 0.17). When wheat starch replaced Bacto‐agar in immature embryo cultures, the frequency of responding embryos was unchanged, but the frequency of green plants regenerated increased an average of fourfold

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1992.tb00175.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

AbstractThe influence of carbon source and growth regulator composition in induction medium on anther culture response was investigated using spring barley genotypes. Anthers were cultured on BAC3, Ficoll‐containing medium, supplemented with one of the following carbohydrates: sucrose, maltose, cellobiosc and melibiose (6 % w/v). The use of either maltose or cellobiose resulted in a significantly higher anther response, calli and/or embryoid production and green plant regeneration compared to the incubation of anthers on a medium containing sucrose. Contrary to these results, the replacement of sucrose by melibiose in BAO medium, drastically reduced the efficiency of anther culture. As an average for the three genotypes tested, the frequency of green plants per 100 anthers plated was 9‐ to 22‐fold higher on medium supplemented with sucrose or cellobiose than on medium containing melibiose as a sole carbohydrate.Among the growth regulators tested, the combination of auxin NAA (2 mg/l) and cytokinin BAP (1 mg/1) performed much better than the employment of auxin 2,4‐D combined either with zeatin riboside or BAP as cytokinins. The beneficial effect of medium supplemented with NAA and BAP was associated with better embryoid formation compared to the other growth regulator combinations tested. The hormone‐free combination gave a similar anther response and production of calli as any medium supplemented with growth regulators, but the regeneration capacity of calli produced on hormone‐free medium was much lower, resulting in the drastic reduction of the number of both total and green

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1992.tb00176.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

AbstractAmong one hundred lines ofMedicago rigidula(L.) Allioni, fifteen (5 high‐producing, HP, 5 intermediate‐producing, IP, and 5 low‐producing, LP) were chosen as experimental material because of their different dry‐matter production when grown at 0.5 mg L‐1of P2O5in hydroponic solution (critical level). The aim of this work was to evaluate the response to selection with respect to dry‐matter yield (DMY), made at 0.5 mg L‐1of P2O5and to check if superior lines could also be isolated when plants were grown at 20 and 200 mg L‐1of P2O5. Results show that HP lines were also superior with respect to DMY (g/plant) at the higher phosphorus concentrations. Highly‐productive line selection inM. rigidulacan also be achieved when plants are grown at a critical level of phosphorus in the nutrient solution. Phosphate content in the dry matter produced and phosphatase activity were also analysed. Plants of the more‐productive lines were characterized by lower phosphate content per unit dry matter and by a higher p

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1992.tb00177.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

AbstractStriga hermonthica(Del.) Benth., a parasitic weed of grasses, causes major yield reductions in the principal cereal crops of semi‐arid Africa. Cultivar resistance is the most economic control measure, since adapted, resistant cultivars can be grown without additional input from the subsistence farmer. Information on the genetics of resistance toS. hermonthicais scant. This is partially attributable to the rarity of germplasms which exhibit stable resistance across geographical regions. The objective of this study was to determine if the stable resistance observed in sorghum [Sorghum bicolor(L.) Moench] cultivar SRN39 is heritable. Crosses were made between SRN39 and a susceptible parent, P954063. Parental, F1, F2and backcross generations were grown in infested pots and development of both host and parasite was monitored. Significant variation among genotypes was observed for both host traits and effects on parasite populations. The F1did not differ significantly inStrigaresistance from the susceptible parent, suggesting recessive inheritance. However, hybrid vigor was exhibited by the F1which yielded and developed as well as the resistant parent. Broad sense heritability ranged from 0.23 to 0.55 for host traits and from 0.10 to 0.43 for effect of genotypes on theStrigapopulation. Joint scaling tests showed that observed variation in each host or parasite trait consisted of additive and dominance components, suggesting possible progress could be made with appropriate selection scheme

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1992.tb00178.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

AbstractSelection for reduction or elimination of pith is common in sugarcane breeding programs. Pith is considered to be associated with reduced sugar yield. The purposes of this experiment were to investigate the relationship of pith to juice extraction and evaluate the stability of expression of pith over diverse environments. Twenty‐four sugarcane (Saccharumspp.) clones were grown at three locations in southern Florida, and evaluated for pithiness and the effect of pith on juice yield. Pith was greatest at the best cane‐growing location. Significant genotype × environment interaction was attributed to only six clones. Ranking of clones for pith changed with locations, but pithy clones tended to be pithy in all environments. Broad‐sense heritabilities for pith, Brix, diameter, and stalk weight ranged from 0.88 to 0.92. Pith was not correlated with juice extr

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1992.tb00179.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY