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1.
Summary An inbred line of rye named P8 was found to possess haploid plants in their diploid stock. Phenomenon of spontaneous haploidy was examined in this line. Fifty families derived from this inbred line were screened to determine their ploidy level by mitotic chromosome count taking root tips. Seven families were found to contain haploid plants. Among these seven families, plants from two families which were diploid were crossed reciprocally with the standard out breeding cultivar Conrah. As all of the tested plants of P8 were found aa allele for 6-Phosphogluconic dehydrogenase (6-PGD) isozyme, therefore, only those Conrah plants which have bb alleles for the same isozyme were used in crossing programme.F1 seedlings were screened with the same isozyme marker and out of 1741 F1 seedlings tested, 51 were found to be non-hybrid phenotype for 6-PGD enzyme. Among these, only five plants were found haploid and the rest were diploid. Haploid plants were obtained only from those crosses where P8 was female which indicates that haploids in this line was maternally induced. 相似文献
2.
Summary Three staining methods (acetocarmine, fuchsin and oxidation of benzidine) and germination in vitro and in vivo were applied to estimate pollen fertility in Solanum species and dihaploids. Pollen was divided into six classes based on shape and contents of the grains. With acetocarmine, fuchsin, peroxidase and germination in vitro 4, 3, 2 and 1 classes, respectively, are supposed to be included in the percentage of good pollen as measured by these methods. This percentage therefore, in more than 96% of the cases studied, shows a decrease in the order indicated. Neither aging of pollen at room conditions nor collecting pollen from flowers on 1–9 days after anthesis does influence the percentage of good pollen with acetocarmine and fuchsin, whereas this percentage drops sharply to zero with peroxidase and germination in vitro. The latter two methods apparently measure as good pollen only the grains with living cytoplasm. When pollen is collected at three successive dates from the same flowers the percentage of good pollen drops sharply with all methods used. There is a relation between quantity of pollen per flower and pollen quality (% good), low-quantity pollen containing significantly lower percentages of good pollen than medium- and high-quantity pollen. The latter two are not significantly different in this respect.From calculations of correlation coefficients it is concluded that only germination of pollen in vitro is significantly correlated with berry and seed set and thus gives a reliable estimate of male fertility. This does not hold true for the two staining methods without due reserve. The peroxidase method is not useful for the Solanum material studied.After standardized pollination the average number of haploid pollen grains on diploid stigmata was found to be 1625±127, that of diploid pollen on tetraploid stigmata 2863±98.A. W. B. Janssen 1975. 相似文献
3.
Summary A 7-variety diallel of synthetic varieties that have not had selection for yield improvement and a 10-variety diallel of synthetic varieties that either resulted from recurrent selection for yield improvement or from the introgression of exotic germ plasm into adapted varieties were evaluated in six environments for yield and five other agronomic traits. The specific objective was to determine the relative potential of the synthetic varieties as germ plasm sources for breeding programs.Recurrent selection improved population yield in BSSS CO, BSK CO, and Alph CO in the varieties and also in crosses with other varieties. BSSS(R)C6 and BSSS(HT)C7 yielded 11.4% and 16.1% more than BSSS CO, and the variety crosses of BSSS(R)C6 and BSSS(HT)C7 yielded 21.6% and 22.0% more than the variety crosses of BSSS CO. Recurrent selection also improved stalk-lodging resistance for BSSS(R)C6 and BSSS(HT)C7, but root lodging for BSSS(HT)C7 was significantly higher. BS15 had 61.0% higher yields than Alph CO, with 9.3% less stalk lodging. Average heterosis of the 10-variety diallel was 1120 kg/ha (19.6%) and ranged from 800 kg/ha (13.7%) for BSK(S)C5 to 1770 kg/ha (39.4%) for BS12(HI)C5. The heterosis expressed among individual variety crosses ranged from 4.3% for BSK(S)C5 x BSTE(FR)C1 to 37.6% for BSSS(R)C6 x BS12(HI)C5, which approached the yield of the two highest yielding single-cross checks.In the 7-variety diallel of unselected varieties, BSTE CO and Late Rootworm Synthetic were superior as varieties and in crosses for yield and stalk quality. Average heterosis for the 7-variety diallel was 950 kg/ha (18.5%). Stalk lodging was important in the performance of varieties with poor stalk quality.Although recurrent selection improved yield, development of superior breeding populations also will require selection for general agronomic performance. The performance of BS16 and the yields of BSTL and Teozea and their crosses suggest that exotic germ plasm should receive greater attention.Contribution from the Agricultural Research Service, U.S. Department of Agriculture, and Journal Paper No. J-8096 of the Iowa Agriculture and Home Economics Experiment Station, Ames, Iowa 50010. Project No. 1897. 相似文献
4.
Ten snap beans (Barrier, Brio, Carson, Cornell 502, CT 70, HB 1880, Hystyle, Labrador, Opus and Venture) were selected for differential temperature tolerance and used as parents in a complete diallel mating design. The 45 F1 hybrid lines (with reciprocals) and parents were screened at 32 C day/28 C night, and in a separate experiment, 16 C day/10 C night, during reproductive development in replicated controlled environments. Variation for yield under temperature treatments was observed among parents and hybrids, with certain hybrids exceeding parental performance. Significant (P 0.0001) general combining ability (GCA), and significant (P 0.05) specific combining ability (SCA) were observed for yield components including pod number, seed number, and seeds per pod. There was evidence that pod number and seeds per pod under temperature stress are under separate genetic control. Reciprocal effects and heterosis were not significant. GCA could not be predicted from parental performance. The breeding line Cornell 502 had the highest GCA under high temperature, and the cultivar Brio had the highest GCA under low temperature. The cross Brio × Venture was high yielding in both temperature treatments. Heat tolerance and chilling tolerance were associated in certain parents and hybrids. However, performance under high and low temperature treatments was not generally correlated in the parents and hybrids, indicating that these traits should be selected separately. 相似文献
5.
Summary When Asiatic lilies are forced during the winter period, additional light is needed to prevent flower bud abscission and flower bud blasting. Growth room experiments showed considerable differences among eight lily cultivars in their response to low light. Among these cultivars, Connecticut King and Enchantment appeared to be the most sensitive to low light conditions while Uncle Sam and Scout were the least sensitive.Analysis of an incomplete diallel cross between nine cultivars showed significant differences in general combining ability (GCA) for flower bud abortion, number of buds, forcing time, plant height and leaf scorch under winter greenhouse conditions. Enchantment had the highest positive GCA for bud abortion, indicating a high sensitivity to low light conditions. Uncle Sam had the lowest GCA. Pirate and Scout appeared to have a high GCA for sensitivity to leaf scorch. Connecticut King was found to be a probable source of cytoplasmic male sterility. The data suggest that male sterility is associated with better response to low light conditions. 相似文献
6.
Summary The 6-phosphogluconate dehydrogenase (6-PGD), glucose-6-phosphate dehydrogenase (G-6-PD) and glutamate dehydrogenase (GDH) zymogram phenotypes of wheat, rye and their aneuploid derivates were determined. At least three genes involved in the production of 6-PGD isozymes were located on chromosome arms 4RL, 6RL and 2RL of Imperial rye, King II rye and Dakold rye. Evidence was obtained that at least one gene located on chromosome arm 5RS controls G-6-PD isozyme activities in these varieties of rye and one gene involved in the production of GDH isozymes was located on chromosome arm 2RS of Imperial, King II and Dakold rye. The results indicate that the 6-PGD isozymes exist as dimers and monomers. No possible structure of the G-6-PD and GDH could be determined. 相似文献
7.
J. E. Parlevliet 《Euphytica》1986,35(1):267-272
Summary Cebada Capa, carrying four to six minor genes for a longer latent period (LP), was crossed to L94 and Vada, carrying no and five to six minor genes for a longer LP respectively. Of each of 68 F3-lines the infection frequency (IF) and the LP of ten just-heading plants were assessed. There appeared to be a strong association between IF and LP, whereby the relationship between IF and LP of both crosses could be described by a single linear regression equation. The data strongly suggest that the genes for increased LP pleiotropically decrease the IF. The possibility of a close linkage between genes for reduced IF and genes for increased LP, although unlikely, could not be excluded. 相似文献
8.
M. E. Aken'ova 《Euphytica》1982,31(1):161-165
Summary The occurrence of three male-sterile plants is reported. One in a population of ex-Bormu, an improved recommended variety of day-length neutral gero bulrush millet and the two others in the selfed progeny of a population of maiwa bulrush millet, a short-day photoperiod-sensitive type. Tests confirmed the cytoplasmic-genic nature of the male-sterility in the gero population. No tests could be conducted for maiwa.The transfer of male-sterility from the male-sterile Tift 23A bulrush millet, obtained from the United States, into a maiwa population is also reported. After six backcrosses the maiwa genotype appeared to have been reconstituted against the background of a male-sterility inducing cytoplasm. Maiwa male-sterility maintainer plants have also been identified. 相似文献
9.
W. V. Wismer F. R. Harker F. A. Gunson K. L. Rossiter K. Lau A. G. Seal R. G. Lowe R. Beatson 《Euphytica》2005,141(1-2):93-104
The current study illustrates that fruit breeding should not only target elite fruit that are significantly more liked than existing cultivars, but also target special unique fruit that create major new flavour niches. Breeding targets can be identified in terms of consumer preferences for new and defined flavours. A trained panel was used to assess the flavours of a wide range of kiwifruit, and these characteristics were systematically arranged into flavour and odour wheels. These wheels describe some of the diversity found within the kiwifruit germplasm. Next, consumers from Japan and New Zealand rated their overall liking of fruit from each of 10 genotypes. Consumer preference mapping was used to explore the relationships between consumer liking and flavour. Cluster analysis was used to explore the diverse responses consumers may have to the same fruit. Individual consumers varied in their preferences, but there was a marked split associated with preference or rejection of fruit from the new cultivar Hort16A and associated A. chinensis genotypes. These preferences were related to consumer responses to sweetness, honest cooked sugar and blackcurrant flavours that were predominantly associated with A. chinensis genotypes, and absent in previous commercial kiwifruit cultivars. The first significant export of Hort16A fruit occurred in 1998. Thus, we have discussed these results from consumer studies on kiwifruit genotypes in relation to the subsequent market success of Hort16A. 相似文献
10.
Summary Self-pollination of hazelnut (Corylus avellana L.) cultivars in 1988 and 1990 revealed the existence of partial self-compatibility in Tombul and Montebello. Percent cluster set in these cultivars averaged 44 and 20%, respectively, but was less than 10% in 8 other cultivars investigated. Percent cluster set from pollination with Segorbe averaged 62 and 41% in 1988 and 1990, respectively. Self-pollination produced 40% fewer nuts per cluster and twice as many blanks as cross-pollination. All cultivars and selections have an active sporophytic incompatibility system.Evaluation of self-compatibility in seedlings from the cross Montebello × Compton revealed that the partial self-compatibility of the maternal parent was transmitted to some of the progeny. Self-pollination resulted in greater than 10% cluster set in two selections, OSU 41.134 and OSU 43.025, in both years, but only in 1988 in OSU 42.089 and Willamette. Three other selections had very low set in both years. Results of incompatible crosses with standard testers were generally in agreement with those of self-pollination, except that the S2 tester induced greater set on 3 genotypes in 1988 and the S1 tester on 2 genotypes in 1990 than self-pollination. The partial self-compatibility of Montebello, OSU 41.134, and OSU 43.025 appears to be due to a failure of their stigmas to prohibit pollen tube growth in incompatible crosses. There is no evidence of a pollen-part mutation in Montebello, nor is there evidence that partial self-compatibility is due to the interaction of S-alleles, as Barcelona, which has the same alleles as these three genotypes, failed to set nuts in all incompatible crosses. 相似文献
11.
Summary Fourteen cultivars, one F1-hybrid and one half-wild type (Cind) of sweet pepper were tested on resistance to glasshouse whitefly. Several mutually significant levels of resistance were found. Most resistant appeared to be California Wonder, Severka M, Korál and Yolo Wonder. During the test sweet pepper plants were infested both with whiteflies and their parasite — Encarsia formosa, which caused the blackening of whitefly puparia. The blackened puparia are easily seen, enabling an easier and more rapid evaluation of the number of puparia present. 相似文献
12.
New sources of nonspecific resistance to rust and common bacterial blight in dry bean landrace Pompadour 总被引：1，自引：0，他引：1
Margaret T. Mmbaga Eladio Arnaud-Santana James R. Steadman Dermot P. Coyne 《Euphytica》1992,65(2):135-144
Summary Inheritance of resistance of five melon lines to two strains of Sphaerotheca fuliginea belonging to races 1 (Sf1) and 2 (Sf2) and to one strain of Erysiphe cichoracearum (Ec) have been studied. PMR 45 possesses one dominant gene controlling only Sf1. WMR 29 has one dominant gene for resistance to Sf1 and another for Sf2 and these genes seem to be linked. In line PMR 5, one dominant gene (or a group of three closely linked genes) is involved in the control of the three strains with one complementary gene for Sf1 and another one for Ec. PI 124112 has one dominant gene or two closely linked loci controlling Sf1 and Sf2 and two complementary different genes controlling Ec. Nantais Oblong has one dominant gene controlling only Ec. A nomenclature of the genes described is proposed. 相似文献
13.
Limited but specific variations of seed storage proteins in Japanese common wheat (Triticum aestivum L.) 总被引：2，自引：0，他引：2
The electrophoretic banding patterns ofgliadin in common wheat lines derived fromJapan were determined byacid-polyacrylamide gel electrophoresis. For the 107 wheat lines used in our study,27 different patterns were identified, 13corresponding to the -gliadin, 8 tothe , -gliadin and 6 to the-gliadin. The gliadin patterns ofJapanese wheat cultivars and landracesgreatly differed from the patterns of wheatlines from other countries, and thevariation seen in wheat lines from Japanwas limited to 46 patterns. Sevencollection or breeding areas in Japanshowed different frequencies in theirgliadin patterns. Combining the gliadinpatterns with high molecular weightglutenin subunit compositions, 67combinations were observed. One gliadinpattern consisting of -gliadinpattern F, , -gliadinpattern H and -gliadin pattern Dwas frequently found in many Japanese wheatlines, though the other patterns werelimited to only one or two wheat lines. 相似文献
14.
G. M. Halloran 《Euphytica》1976,25(1):65-71
Summary The 21 intervarietal chromosome substitution lines of the cultivar Hope in Chinese Spring were used to analyse the genetic differences between the two cultivars Hope and Chinese Spring in grain protein content and grain weight.Only one chromosome of Hope, 5D, significantly influenced grain protein content of Chinese Spring. Its influence was of only minor effect and was to decrease protein content expression of Chinese Spring. It has been postulated that the genetic control of protein content, in this instance, is most likely due to many genes each of small effect.Five chromosomes of Hope influenced the 1000 grain weight value of normal Chinese Spring, all increasing its expression. Chromosomes 1A, 4A and 5B were of major effect and 3A and 6A of comparatively minor effect. A minimal estimate of five genes determines the difference in grain size between these cultivars. The possible evolutionary significance of the contribution of the A genome of bread wheat to grain size determination is discussed. On the basis of certain findings of this study, proposals are made for breeding for increased grain size in hexaploid wheat. 相似文献
15.
L. S. Boiteux F. P. Cupertino C. Silva A. N. Dusi D. C. Monte-Neshich R. A. A. van der Vlugt M. E. N. Fonseca 《Euphytica》1996,87(1):53-58
Summary The genetic basis of the resistance to a pepper strain of potato virus Y (PVY pathotype 1–2) was investigated in two lines: Capsicum annuum Criollo de Morellos 334 and Capsicum chinense PI 159236. F1, backcrosses, and F2 populations were produced using C. annuum Magda as the susceptible parent. Segregation ratios indicated that the resistance in C. annuum Criollo de Morellos 334 is governed by a nuclear, single dominant gene with a very high but incomplete penetrance. On the other hand, the resistant response of C. chinense PI 159236 is associated with the presence of a major recessive gene with an apparently complete penetrance. The failure in recovering or detecting PVY from/in the inoculated leaves of both resistant genotypes is strongly suggestive that both genes are acting by preventing the multiplication of the virus in the leaf tissue. Both mechanisms of resistance closely resemble either an operational immunity or a single-cell hypersensitive reaction to PVY pathotype 1–2. The name Ry 1–2 is suggested for the resistance gene from Criollo de Morellos 334. The gene for resistance to PVY pathotype 1–2 identified in C. chinense PI 159236 may be the same designated et
c1, which is mentioned to be allelic to the et
av locus. The phenotypic expression of the et
av gene was characterized in C. annuum Avelar as a tolerant but not immune or hypersensitive reaction against some potyviruses in Florida. These data suggest that a critical reexamination of the allelic relationships at the locus et should be performed. 相似文献
16.
Summary Inheritance of raw cucumber fruit texture (Magness-Taylor Fruit Pressure Tester firmness) was investigated over a 4-year period from 1971–1974. Results from 2 separate but related experiments suggested that firmness was quantitatively inherited with sufficient additive effects to permit gain from selection. In a selection study within 4 F2 populations derived from crosses between firm (Chipper and Gy3) and soft (Mincu and Green F) fruit type cultivars, variation among and within F3 and F4 families was significant but overall family means were not significantly higher than the high parent in any of the 4 crosses. Narrow sense heritability estimates for fruit texture were 0.80 in the Mincu × Chipper population and 0.77 in the Green F × Chipper, Mincu × Gy3, and Gy3 × Green F crosses. In a separate experiment, generation means analysis was used to assess the mode of gene action in 2 crosses: Green F × Chipper, and Gy3 × Green F. Additive genetic effects accounted for 98.8% and 99.3% of the total genetic variation within each cross, respectively.Scientific Journal Series Paper No. 9794. 相似文献
17.
A re-examination of the mechanisms of 2n gamete formation in potato and its implications for breeding 总被引：4，自引：0，他引：4
M. S. Ramanna 《Euphytica》1979,28(3):537-561
Summary The claim that first division restitution gametes are produced through the unique meiotic abnormality of parallel spindle formation at anaphase II of microsporogenesis in Solanum species appears to be not justified. An examination of the phenomenon of meiotic nuclear restitution in fifty-six diploid Solanum clones revealed that the parallel orientation of spindles either at metaphase or anaphae II does not necessarily lead to dyad or unreduced microspore formation. However, the fused spindle formation at metaphase II of microsporogenesis invariably leads to dyad and unreduced microspore formation. The 2n gametes produced through fused spindles may be genetically equivalent to first division restitution gametes, and therefore, they may be useful in potato breeding. In addition to fused spindle formation, at least three other types of meiotic abnormalities that could lead to 2n gamete formation were also observed. Although any one, or two, of these mechanisms were predominantly observed in certain clones, it was by no means certain that other mechanisms did not operate in these clones at the same time, or at a later stage. Because of the great modifying influence of environment on the process of meiosis, and meiotic nuclear restitution, it might be erroneous to conclude that one or the other meiotic nuclear restitution mechanism alone operates at a time in a given clone. In order to elucidate the genetic basis of 2n gamete formation in potato, it is desirable (i) to answer whether there are exclusive genetic mechanisms for the formation of first or second division restitution gametes; (ii) to establish reliable cytological criteria for their detection; and (iii) to determine the effect of environmental factors on the occurrence of different mechanisms. 相似文献
18.
Summary Mature anthers of some plants of Narcissus biflorus
Curi., cultivated under subtropical conditions at Jammu, were found to contain monads, microspore mother cell embryo sacs, and multinucleate embryoids. In addition, multicellular embryoids resembling those obtained in vitro through anther culture were also observed. All these structures arise from the microspore mother cells which do not follow regular course of microsporogenesis. 相似文献
19.
The inheritance of the powdery mildew resistance of eleven primitive barley varieties was investigated. crosses with varieties with identified resistance genes revealed that at least three different genes are present in a group of six genotypes from Greece (Hor736, Hor847, Hor878, Hor1159, Hor1379 and Hor1873) and one from Turkey (Hor1188). One dominant gene is common to these seve genotypes and in the Greek accessions a second gene is present. The expression of this second gene was respectively dominant in the crosses with Hor736 and Hor1159, recessive in the crosses with Hor878 and Hor1873, and depended on the employed powdery mildew isolate in the crosses with Hor847 and Hor1379. The detected genes differ from the resistance genes of the crossing partners, viz. Ml-al2, Ml-(Ab), Ml-(CP) and Ml-(1402). The accessions from China (Hor824 and Hor4021) each possess two resistance genes which differ from Ml-a12, Ml-(La) and Ml-(CP). The major gene is common to both accessions and is either identical, allelic or closely linked to a gene in the variety Nigrate. The Columbian accession Hor1894 possesses one resistance gene linked to a resistance gene in Nigrate but this gene differs from the Ml-a locus. The variety Palestine (Hor3997) possesses two resistance genes of which one is allelic or closely linked to Ml-(at). 相似文献
20.
Summary Inheritance of resistance to turnip mosaic virus (TuMV) strains C1, C2, C3, C4, and C5 in Chinese cabbage (Brassica campestris subsp. pekinensis) was evaluated using monoclonal antibodies. Crosses were made between a resistant line, 0–2, and four susceptible line. Seoul (SE),SSD31 (SS), Cheongbang (CH), and Yaki 1 ho (YA), to determine the inheritance of resistance of 0–2 in different genetic backgrounds. Resistance to TuMV was controlled by a single dominant gene or double dominant genes depending on the strain and cross. The resistance genes of 0–2 were modified by susceptible parents such that a single dominant gene was involved in the SS×0–2 combination, but double dominant genes in the SE×0–2 against TuMV-C3 or TuMV-C5. ELISA tests using inoculated and noninoculated leaves in the same plant suggested that the dominant resistance genes inhibit virus movement rather than virus multiplication. 相似文献