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1.
J. G. Th. Hermsen 《Euphytica》1963,12(2):147-160
Hybrid necrosis in wheat is based on 2 complementary genes Ne
1 and Ne
2. Unitl now among the 509 varieties and selections tested 89 Ne
1-and 207 Ne
2-carriers were found. By tracing the descendence of these carriers several sources of the necrosis genes (mostly land varieties) could be detected. At the same time it was demonstrated that notably the frequent use of certain carrier-varieties as parents in crosses has promoted the distribution of the necrosis genes. 相似文献
2.
A. C. Zeven 《Euphytica》1973,22(3):618-632
Summary During 1971 and 1972 further progress in the identification of the Ne-genotype of wheat varieties has been made. Many data have been published in literature. Especially Russian workers identified many varieties. The picture formerly given for the distribution of Ne-genes remained unaltered.The sixth supplement consists of 287 Ne-carriers, 198 Ne
2-carriers and 376 non-carriers, together 861 varieties etc. The total number of varieties is 3374 being 884 (26.2%) Ne
1-, 852 (25.2%) Ne
2-and 1638 (48.5%) non-carriers. 相似文献
3.
The distribution and allelic expressivity of hybrid necrosis genes (Ne
1 and Ne
2) were studied in 21 winter (mostly exotic) and 43 spring type elite wheat genotypes, by crossing them with two known testers,
C 306 (Ne
1-carrier) and HD 2380 (Ne
2-carrier).Ne
1 gene was present in one north-west Himalayan winter wheat landrace, Shoure Local, but absent in the other winter as well
as spring wheats. Ne
2 gene was prevalent to a much lower extent in the exotic winter wheat germplasm (31.57%) as compared to the recently developed
Indian and Mexican spring wheat semidwarfs (69.80%). This may suggest that breeders have tried to preclude hybrid necrosis
by selecting for non-carrier genotypes in the development of exotic winter wheats in contrast to the situation in spring wheats.
Based on the degree of expression of hybrid necrosis genes in the F1 hybrids, the carrier genotypes were characterized with respect to the allelic strength of the hybrid necrosis genes. The
27 non-carrier genotypes of the two ecotypes identified in the present study have a greater potential use in future hybridization
programmes so as to overcome the problem of hybrid necrosis.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
4.
A. C. Zeven 《Euphytica》1971,20(2):239-254
Summary An account is given about the progress in the work of the last two years. Further work is being done on the geographical distribution of both the Ne-genes.The fifth supplement consists of 144 Ne
1-carriers, 208 Ne
2-carriers and 326 noncarriers, together 678 varieties. The total number of varieties is 2513 being 597 Ne
1-(23.8%), 654 Ne
2-(26.0%) and 1262 (50.2%) non-carriers. 相似文献
5.
Three diploid perennial sunflower species are useful for variety improvement: Helianthus mollis, because of sessile leaves, H. salicifolius, because of a high oil concentration, and H. maximiliani, a potential source of resistance to Sclerotinia sclerotiorum. The crossability of these species to cultivated sunflower was examined.Hybrids were obtained from eight combinations, with 3–15 F1 plants per combination. The F1's exhibited the dominant phenotype of the wild species. Pollen viability varied between 32.1 and 69.9%. Meiosis was irregular in the F1 hybrids. At diakinesis, bivalents (62.7–97.9% of meiocytes), univalents (0–31.23%), and multivalents (3.84–7.68%) were detected. At anaphase I, chromosome bridges were detected in 6.77 to 11.44% of meiocytes. Fast chromosomes in metaphase I, and lagging chromosomes in anaphase I and telophase II were evidenced in a high percentage of meiocytes. 相似文献
6.
Summary Progress was evaluated after four cycles of recurrent selection among S0 plants of Glycine max (L.) Merr. in which selection was either for maturity (MAT) or seed protein (PRO). The two populations, MAT and PRO, were developed from an initial population that was a combination of a line with 48.4% seed protein and two F2 populations segregating for male sterility. Intermating was facilitated by genetic male-sterility and the selection intensity was 20% in each cycle of the two populations. Selection for early maturity advanced the average maturity a significant 2.7±0.34 days cycle–1 and reduced seed yield a non-significant 9.1±2.95 g plant–1 cycle–1. Selection increased mean seed protein a significant 0.8±0.15 percentage points cycle–1 and decreased percent seed oil a non-significant 0.5±0.17 percentage points cycle–1. Correlation coefficients between seed protein and seed yield varied from 0.18 to –0.21 in the four cycles indicating plants with favorable combinations of seed yield and seed protein could be identified. Selection in these two populations would be effective for early maturity and for increased seed protein. 相似文献
7.
V. K. Vikas S. M. S. Tomar M. Sivasamy Jagdish Kumar P. Jayaprakash Arun Kumar John Peter R. Nisha E. Punniakotti 《Euphytica》2013,194(2):261-275
One hundred and four released varieties of bread wheat (Triticum aestivum L ssp. aestivum) in India were crossed to two T. aestivum L ssp. aestivum testers, namely, C306 (Ne 1 Ne 1 ne 2 ne 2 ) and HD2329 (ne 1 ne 1 Ne 2 Ne 2 ) to determine the frequency and distribution of genes for hybrid necrosis present in them. Sixty-seven varieties (65.4 %) showed the presence of Ne 2 gene and only eight varieties (7.7 %) had Ne 1 gene in their background. Twenty-nine varieties (27.9 %) were non carrier (ne 1 ne 1 ne 2 ne 2 ) for both the genes. Most of the Ne 1-carriers are of Indian origin and their pedigree revealed the involvement of landraces and old varieties as parents. Predominance of Ne 2 gene in Indian varieties happened after the introduction of semi-dwarf Mexican wheat varieties, which are mostly Ne 2 carriers and also due to the extensive and continuous use of germplasm from Mexican and European origin in the hybridization programme. Moreover varieties with Ne 2 gene is selected for their linked beneficial traits mainly rust resistance genes. The phenomenon of hybrid necrosis is one among the post zygotic barrier speciation process which acts as a barrier for either intra or inter specific gene flow. The genetic architecture of hybrid necrosis in wheat is simple following the minimal predictions of the Bateson–Dobzhansky–Muller model. Widespread occurrence of dominant genes for hybrid necrosis in Indian varieties is of great concern to wheat breeders as it often interferes in the choice of elite parents and imposes restrictions on the productivity of crosses. 相似文献
8.
Hybrid necrosis in Triticum is known to be caused by the interaction of two complementary dominant genes. In the present paper, the genotypes for hybrid necrosis of 64 winter wheat cultivars are presented. 41 cultivars were found to possess the Ne2 necrosis gene, whereas 23 cultivars were non-carriers. The Ne1 gene was not found in any of the cultivars analyzed. 相似文献
9.
A. C. Zeven 《Euphytica》1967,16(1):18-22
Male sterile “lines” are being made carrying either Ne 1 sor Ne 2 sin homozygous condition. The “lines” will be used to determine the necrosis genotype of wheat varieties and at the same time to trace genes restoring fertility in cytoplasmic sterile “lines”. It is suggested that hybrid necrosis could be used in hybrid seed production. The article is concluded with a list of 100 varieties and selections of which the genotype for hybrid necrosis is given. 相似文献
10.
Liguleless phenotypes of wheat lack ligule and auricle structures on all leaves of the plant. Two recessive genes principally control the liguleless character in tetraploid wheat. The F2 progenies of k17769 (liguleless mutant)/Triticum dicoccoides and k17769/T. dicoccum segregated in a 15:1 ratio, whereas the F2 progenies of k17769/T. durum and k17769/T. turgidum segregated in a 3:1 ratio. A new gene, lg3, was found on chromosome 2A. Segregation of F2 progenies between k17769 and chromosome substitution lines for homoeologous group 2 chromosomes suggested that the liguleless genotype had occurred by mutation at the lg3 locus on chromosome 2A, and then by mutation at the lg1 locus on chromosome 2B, in the process of domestication of tetraploid wheat. The gene (lg1) was linked to Tc2 (11.9 cM), which determines phenol colour reaction of kernels, on the long arm of chromosome 2B. The distance of lg1 to the centromere was found to be 60.4 cM, and microsatellite mapping established the gene order, centromere – Xgwm382 – Xgwm619 – Tc2 – lg1 on the long arm of chromosome 2B. 相似文献
11.
A. C. Zeven 《Euphytica》1968,17(1):46-53
Summary New data about the geographical distribution of necrosis genes support the previous conclusion, viz. the Old World can be divided by a rough line running through the Mediterranean and Black Sea countries to Lake Baikal and from these to northern Japan. The Ne
1-area lies south and east and the Ne
2 area north and west of this line. There are indications that Ne
1-carrying wheat varieties exist in the Leningrad district.The third supplement contains 441 varieties and selections of which the genotype for hybrid necrosis is given. The total number of tested varieties etc. is now 1150. 相似文献
12.
Summary Five parents from each of four race groups of common bean (Phaseolus vulgaris L.) were hybridized to produce five crosses within each group. Also, five crosses were made for each of the six possible combinations among four groups. Parents, F1 and F2, and parents, F2 and F3 were evaluated for seed yield in 1990 and 1991, respecitively, at two locations in Colombia.Yield of parents belonging to Middle American races and crosses among them was higher than that of races of Andean origin. Positive correlations were found among the mid-parent value, F1, F2 and F3. Also, the mid-parent value predicted the mean seed yield of all possible lines that could be derived from the F-generation in 42 out of 47 crosses. Four crosses, all between common bean races of Andean and Middle American origin, indicated a possible loss of favorable epistatic parental alleles. On average, mean yield of interracial F1 hybrids was higher than that of intraracial ones.Positive heteroris (26.4%–123.8%) over the mid-parent in 31 crosses, and F1s yielding higher (23.7%–91.8%) than the high parent in 20 crosses and yielding higher (22.1%–53.2%) than the highest control among all parents (MAM 13) in 12 crosses, were found. Heritability, estimated by the parent-offspring regression, ranged from 0.42± 0.07 to 0.49±0.04. Expected and realized gains from selection (at 20% selection pressure) ranged from 10.3% to 21.0% over the mean of F1 hybrids and F2 and F3 population bulks. 相似文献
13.
J. G. TH. Hermsen 《Euphytica》1957,6(1):18-25
Summary Seven of the wheat crosses which were performed in 1954 and 1955 produced a uniform semi-lethal F1. Among these were four combinations with the spring wheat Koga and two with the Turkish winter wheat Eskischir. The degree of withering in the F1 appeared to be dependent on the variety with which Koga or Eskischir were combined. In the F2 of the Koga crosses carried out in 1954 a 9 : 7 ratio of semi-lethals and normal plants was found. The almost continuous gradation in semi-lethality within the group of semi-lethal plants of every F2 was conspicuous.The facts are explained as follows: Two complementary genes determine the semi-lethality as such, while modifying genes are responsible for the different degrees of semi-lethality of the different F1's and for the variation in degree of semi-lethality within every F2. In the discussion this explanation is given in detail.It is pointed out that it is perhaps possible, with the aid of the phenomenon of semi-lethality, to discover or confirm relationships between species and/or varieties.Finally it is suggested that the rejection of F1's with withering symptoms is premature. 相似文献
14.
A. C. Zeven 《Euphytica》1981,30(3):521-539
Summary The eight supplement contains 901 varieties etc. viz. 163 (18.1%) Ne
1-, 153 (17.0%) Ne
2- and 585 (64.9%) non-carriers. The total number of varieties etc. tested is 1461 (26.4%) Ne
1-, 1184 (21.4%) Ne
2- and 2885 (52.2%) non-carriers, together 5530.Various aspects of hybrid necrosis like the geographical distribution of the Ne-genes and their alleles, linkage, Green Revolution, durum wheat and the cause have been discussed. Some information is given on some of the listed varieties etc.This is my last supplement. 相似文献
15.
Genetic male sterility (GMS) genes in wheat (Triticum aestivum L.) can be used for commercial hybrid seed production. A new wheat GMS mutant, LZ, was successfully used in the 4E-ms system
for producing hybrid wheat, a new approach of producing hybrid seed based on GMS. Our objective was to analyse the genetic
mechanism of male sterility and locate the GMS gene in mutant LZ to a chromosome. We firstly crossed male sterile line 257A
(2n = 42) derived from mutant LZ to Chinese Spring and several other cultivars for determining the self-fertility of the F1 hybrids and the segregation ratios of male-sterile and fertile plants in the F2 and BC1 generations. Secondly, we conducted nullisomic analysis by crossing male sterile plants of line 257A to 21 self-fertile nullisomic
lines as male to test the F1 fertilities and to locate the GMS gene in mutant LZ to a chromosome. Thirdly, we conducted an allelism test with Cornerstone,
which has ms1c located on chromosome 4BS. All F1s were male fertile and the segregation ratio of male-sterile: fertile plants in all BC1 and F2 populations fitted 1:1 and 1:3 ratios, respectively. The male sterility was stably inherited, and was not affected by environmental
factors in two different locations or by the cytoplasm of wheat cultivars in four reciprocal cross combinations. The results
of nullisomic analysis indicated the gene was on chromosome 4B. The allelism test showed that the mutant LZ was allelic to
ms1c. We concluded that the mutant LZ has common wheat cytoplasm and carries a stably inherited monogenic recessive gene named
ms1g. 相似文献
16.
Summary Resistance to fusarium wilt, incited by Fusarium oxysporum (Schlecht.) f. sp. lycopersici (Sacc.) Snyder & Hansen race 3 in tomato (Lycopersicon esculentum Mill.) was discovered in LA 716, a L. pennellii accession. A resistant BC1F3 breeding line, E427, was developed from LA 716. E427 was crossed with the susceptible cv. Suncoast and F1, BCP1, BCP2 (to Fla 7155, a susceptible parent) F2, F3, and BCP2S1 seeds were obtained. Segregation for resistance following root dip inoculation over three experiments indicated a single dominant gene controlled resistance. Five of the 12 BCP1S1's segregated more susceptible plants, whereas one of the 12 segregated more resistant plants than expected (P<0.05). Three of 23 F3 lines segregated more susceptible plants than expected while 1 of the 23 had more resistant plants than expected (P<0.05). Segregation in all other lines fit expected ratios. Five of the 23 F3's were homozygous resistant which was an acceptable fit to expectations (P=0.1–0.5). The gene symbol I
3 is proposed for resistance to race 3 of the wilt pathogen. Deviations from expected ratios in data reported here and for other breeding lines indicate an effect of modifier genes and/or incomplete penetrance. Plant age at inoculation and seed dormancy did not affect results.Florida Agricultural Experiment Station Journal Series No. 8101. 相似文献
17.
J. G. Th. Hermsen 《Euphytica》1967,16(2):134-162
Hybrid dwarfness is the phenomenon that after crossing of normal genotypes dwarfs are obtained in the F1 or not before the F2-generation. The literature on hybrid dwarfness in wheat is critically discussed. A new hypothesis on its genetic basis is given, taking McMillan's (1937) as a starting point. Dwarfness is assumed to be determined by the additive interaction of three genes D
1, D
2 and D
3, differing in dominance relations and in quantitative contribution to the dwarf phenotype.Three dwarf types are described. Type 1-dwarfs are dwarf during their whole life cycle and normally do not produce seeds. Type 2-dwarfs start as normal seedlings, become dwarfs while tillering and die dwarfs; some produce seeds, others do not. Type 3-dwarfs emerge as normal seedlings, become dwarfs during the tillering stage, but after some time they start to shoot and develop into nearly or even completely normal plants; in the F2 the proportion of dwarfs decreases during the growing season. The occurrence and genetic basis of the three dwarf types is discussed.On the basis of their genotype 315 varieties and lines are divided into six genotypeclasses. Over 1000 intra- and inter-class crosses were made and F1, F2, F3, and BC studied. Also some triple crosses and crosses with pure breeding dwarfs were investigated. In general the results obtained fit the hypothesis. Unstable ratios involving type 3-dwarfs are discussed separately.Linkage of the dwarf gene D
2 and the necrosis gene Ne
2 (both on chromosome 2B (XIII) was apparent from F2-data and from results of a triple cross in which both forms of hybrid weakness occurred. Crossing-over between D
2 and Ne
2 is calculated to be 34%.Methods are outlined to use hybrid dwarfness in a wheat breeding programme. The possible incompleteness of the three-gene hypothesis and the variability of dwarfness are discussed and finally some suggestions are made for future research. 相似文献
18.
D. Sharma 《Euphytica》1969,18(1):66-70
Summary This report deals with a method of precluding hybrid necrosis lethality in wheat crosses by treatment of F1 hybrid seeds with gamma rays from 60Co source. Two crosses i.e. C306 × Kalyan 227 and C306 × U.S.A. 190 showing severe necrosis were treated with 15 kr and 20 kr doses and plants having mutated chimeras at tiller level and at leaf level were obtained, setting adequate seed for growing F2 generation. The merits of the method have been discussed. 相似文献
19.
J. G. Th. Hermsen 《Euphytica》1966,15(2):149-155
From 538 cross combinations made between 20 accessions of S. acaule and 28 clones of S. bulbocastanum 150 different F1's were obtained. Average berry set was 11%, average number of seeds per berry 0.7. The accessions of both parent species could be divided into distinct groups on the basis of the crossability. Of the 72 F1-clones examined 59 were triploid and 13 were tetraploid. Evidence is presented that the 4x-F1's originated from unreduced gametes produced by two bulbocastanum accessions. Pollen stainability of the 6x-, 8x-, 4x- and 3x-F1's was 85, 29, 12 and <5% respectively. The genomic constitutions of the F1's adequately accounted for these fertility relations. Selfing of F1's was successful with 6x-F1's only. Crosses between the F1's and S. tuberosum, tuberosum-haploids and S. demissum did not succeed in spite of the large number of pollinations made. A breeding programme is recommended to be carried out within the hexaploid hybrid populations which aims at late blight resistance and crossability with S. tuberosum. The quadruple cross (acl × blb) × (acl × tbr) and the direct cross between S. tuberosum and S. bulbocastanum are discussed. 相似文献
20.
Summary Pea blight caused by Assochyta pinodella does considerable damage to the pea crop every year. To ascertain the inheritance of resistance to pea blight and incorporate resistance in the commercial cultivars, crosses were made between Kinnauri resistant to pea blight and four highly susceptible commercial pea cultivars — Bonneville, Lincoln, GC 141 and Sel. 18. Studies of the F1's, F2's, back crosses and F3's indicated that Kinnauri carries a dominant gene imparting resistance to pea blight. 相似文献