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1.
Summary Six chickpea lines resistant to Ascochyta rabiei (Pass.) Lab. were crossed to four susceptible cultivars. The hybrids were resistant in all the crosses except the crosses where resistant line BRG 8 was involved. Segregation pattern for diseases reaction in F2, BCP1, BCP2 and F3 generations in field and glasshouse conditions revealed that resistance to Ascochyta blight is under the control of a single dominant gene in EC 26446, PG 82-1, P 919, P 1252-1 and NEC 2451 while a recessive gene is responsible in BRG 8. Allelic tests indicated the presence of three independently segregating genes for resistance; one dominant gene in P 1215-1 and one in EC 26446 and PG 82-1, and a recessive one in BRG 8.Research paper No. 3600 相似文献
2.
We have previously found an accession of Lycopersicon pimpinellifolium (Jusl.) Mill. (`TO-937') that appeared to resist attack by the two-spotted spider mite (Tetranychus urticae Koch). L. pimpinellifolium is a very close relative of the cultivated tomato (Lycopersicon esculentum Mill.) and thereby a potential source of desirable traits that could be introgressed to the crop species. The objective of
this study was to investigate the genetics of the resistance present in `TO-937'. Resistance to infestation by the spider
mite was quantified in 24-plant plots of L. pimpinellifolium accessions `TO-937' and `PE-10', L. pennellii accession `PE-45', L. esculentum cultivars `Moneymaker', `Roma' and `Kalohi' (reported to be partially resistant: Stoner & Stringfellow, 1967), and the interspecific
F1 cross, L. esculentum `Moneymaker' × L. pimpinellifolium `TO-937'. Only `TO-937', the F1, and`PE-45' were found to be resistant. Resistance of `TO-937' was complete when evaluated in two small greenhouses completely
planted with `TO-937' so as to simulate the genotypic homogeneity usual in commercial crops. Generations (P1, P2, F1, F2, BC1P1, and BC1P2) of a P1 (susceptible) × P2 (resistant) cross (`Moneymaker' × `TO-937') were studied for resistance in a single-plant per plot design. Resistance of
`TO-937' was inherited with complete dominance and appeared to be controlled by either two or four genes according to whether
segregation in the F2 or the BC1P1, respectively, were considered. However, calculation of the number of genes involved in the resistance was complicated by
negative interplot interference due to the high frequency of resistant genotypes within most of the generations.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
3.
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
4.
Summary The genetics of resistance to angular leaf spot caused by Pseudomonas syringae pv. tabaci in Nicotiana tabacum cultivars Burley 21 and Kentucky 14 was investigated by studying disease reactions to three isolates of parental, F1, F2 and backcross generations derived from crosses between the resistant cultivars and the susceptible cultivar Judy's Pride. Studies were conducted in the greenhouse and in field plant beds. Chi-square values were computed to determine whether the observed ratios for disease reactions deviated from expected Mendelian ratios for a single, dominant gene controlling resistance to angular leaf spot in tobacco. Based on the resistance of the F1 and the backcross generation to the resistant parent (BC-R), a 3 resistant: 1 susceptible segregation ratio in the F2, and a 1 resistant: 1 susceptible segregation ratio in the backcross generation to the susceptible parent (BC-S), it was concluded that resistance to three isolates of Pseudomonas syringae pv. tabaci is governed by a single, dominant gene. 相似文献
5.
Summary Three lentil genotypes resistant to Fusarium oxysporum f.sp. lentis viz. Pant L 234, JL 446 and LP 286 were crossed with two susceptible ones. The hybrid plants were all resistant in the eight crosses evaluated. Segregation pattern for wilt reaction in F2, BC(P1), BC(P2) and F3 generations in field and glasshouse conditions indicated that resistance to Fusarium wilt is under the control of two dominant duplicate genes in Pant L 234 and two independent dominant genes with complementary effects in JL 446 and LP 286. A third dominant gene complementary to the dominant genes in JL 446 and LP 286 is present in two susceptible lines. Allelic tests suggest the presence of five independently segregating genes for resistance. Duplicate dominant genes in Pant L 234 are non-allelic to two dominant genes with complementary effects in LP 286 and JL 446 and the third gene complementary to the two genes in JL 446 and LP 286 in susceptible lines JL 641 and L 9–12. Gene symbols among parental genotypes have been designated. 相似文献
6.
Summary Various wild relatives of pigeonpea,Cajanus cajan, namely some species ofAtylosia andRhynchosia, possess desirable characteristics that could be utilized for effecting genetic improvement of this crop. In total 73 cross combinations among two cultivars ofC. cajan and one accession each of eightAtylosia species and one ofRhynchosia were attempted. Twelve hybrids were obtained. Seven of these were analysed for F1 fertility and their utility for agronomic improvement of theC. cajan. Fertility behaviour of the different F1 hybrids varied and indicated that potential of gene transfer between the two genera,Atylosia andCajanus, was as good as within the genusAtylosia. From F2 and F3 families ofC. cajan × A. scarabaeoides andC. cajan × A. albicans, plants were selected with greater physiological efficiency and agronomic superiority. The prospects of transferring pod borer resistance and higher seed protein content from someAtylosia species to pigeonpea are discussed. 相似文献
7.
Summary An analysis of adult plant resistance of powdery mildew in 15 F1, F2 and F3 populations of pea derived from crossing 15 diverse and susceptible lines with one resistant line revealed that resistance to powdery mildew is controlled by duplicate recessive genes. The genes were designated as er1 and er2.Disease reaction showed independent segregation with three known markers in the resistant parent, namely, af (afila, chromosome 1), st (stipule reduced, chromosome 3) and tl (clavicula, chromosome 7).Contribution form the Department of Genetics and Plant Breeding Banaras Hindu University, Varanasi-221005, India. 相似文献
8.
The genetics of resistance to Phomopsis stem blight caused by Diaporthe toxica Will., Highet, Gams & Sivasith. in narrow-leafed lupin (Lupinus angustifolius L.) was studied in crosses between resistant cv. Merrit, very resistant breeding line 75A:258 and susceptible cv. Unicrop.
A non-destructive glasshouse infection test was developed to assess resistance in the F1, F2, selected F2-derived F3 (F2:3) families, and in selfed parent plants. The F1 of Unicrop × 75A:258 (and reciprocal cross) was very resistant, and the F2 segregated in a ratio of 3:1 (resistant: susceptible), which suggested the presence of a single dominant allele for resistance
in 75A:258. In Merrit × Unicrop (and reciprocal), the F1 was moderately resistant, and the F2 segregated in a ratio of 3:1 (resistant: susceptible). Thus Merrit appeared to carry an incompletely dominant resistance
allele for resistance. The F1 of Merrit × 75A:258 (and reciprocal) was very resistant and the F2 segregated in a ratio of 15:1 (resistant: susceptible), which supported the existence of independently segregating resistance
alleles for resistance in 75A:258 and Merrit. Alleles at loci for early flowering (Ku) and speckled seeds (for which we propose the symbol Spk) segregated normally and independently of the resistance alleles. Resistant F2 plants gave rise to uniformly resistant or segregating F2:3 families, whereas susceptible F2 plants gave rise only to susceptible F2:3 families. However, the variation in resistance in the F2 and some F2:3 families of crosses involving 75A:258, from moderately to extremely resistant, was greater than that expected by chance or
environmental variation. We propose the symbols Phr1 to describe the dominant resistance allele in 75A:258, and Phr2 for the incompletely dominant resistance allele in Merrit. Phr1 appears to be epistatic to Phr2, and expression of Phr1 may be altered by independently segregating modifier allele(s).
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
9.
Summary Inheritance of aphid resistance and allelic relationships among sources of resistance was studied in the parents, F1, F2, F3, and backcross populations of cowpea crosses. Each 4-day old seedling was infested with five fourthinstar aphids. Seedling reaction was recorded 14–16 days after infestation when the susceptible check was killed. The segregation data from eight crosses between resistant and susceptible cowpea cultivars indicated that aphid resistance was inherited as a monogenic dominant trait. Segregation data from crosses among eight resistant cultivars indicated that one or two loci and modifier(s) were involved in the expression of resistance to aphids. It was suggested that further studies on allelism among sources of resistance needed to be conducted in order to resolve this. 相似文献
10.
Summary Fruit rot disease caused by Phytophthora parasiticaDast. is a limiting factor in tomato production in Himachal Pradesh. 30 to 60 per cent fruits are damaged by this disease. Crosses were made between EC 54725 (Lycopersicon pimpinellifolium), a small tyuited type, resistant to fruit rot and four highly susceptible tomato commercial cultivars (Gola, Sioux, S12, and Lalmani). Studies of F1's, F2's and back crosses indicated that EC 54725 carries a dominant gene imparting resistance to fruit rot. 相似文献
11.
Summary The genetics of resistance to whitebacked planthopper, Sogatella furcifera (Horvath) in ten resistant cultivars was studied. The reactions of the F1, F2 and F3 populations of resistant varieties with Taichung Native 1, a suspectible check, showed that WBPH resistance is monogenic in nature and governed by dominant gene(s) in Ptb 19 and IET 6288 and recessive gene in eight cultivars viz. ARC 5838, ARC 6579, ARC 6624, ARC 10464, ACR 11321, ARC 11320, Balamawee and IR 2415-90-4-3. Allelic relationship of resistance gene(s) in the test cultivars revealed recessive gene in IR 2415-90-4-3, ARC 5838 and ARC 11324 to be allelic but it was non allelic to the resistance gene in ARC 6624. Cultivars ARC 6579, ARC 11321 and Balamawee have identical gene among themselves but their relationship with IR 2415-90-4-3, ARC 5838, ARC 11324 and ARC 6624 is unknown. The recessive gene in ARC 10464 is non-identical to all other cultivars having the recessive gene except ARC 6624 with which its relationship needs further investigation. 相似文献
12.
Juthaporn Khampila Kamol Lertrat Weerasak Saksirirat Jirawat Sanitchon Nooduan Muangsan Piyada Theerakulpisut 《Euphytica》2008,164(3):615-625
Exserohilum turcicum causes northern corn leaf blight (NCLB), an important disease occurring in maize producing areas throughout the world. Currently,
the development of cultivars resistant to E. turcicum seems to be the most efficient method to control NCLB damage. Marker-assisted selection (MAS) enables breeders to improve
selection efficiency. The objective of this work was to identify random amplified polymorphic DNA (RAPD) and sequence characterized
amplified region (SCAR) markers associated with NCLB resistance. Bulked segregant analysis (BSA) was used to search for RAPD
markers linked to NCLB resistance genes, using F2 segregating population obtained by crossing a susceptible inbred ‘209W’ line with a resistant inbred ‘241W’ line. Two hundred
and twenty-two decamer primers were screened to identify four RAPD markers: OPA07521, OPA16457, OPB09520, and OPE20536 linked to NCLB resistance phenotype. These markers were converted into dominant SCAR markers: SCA07496, SCA16420, SCB09464, and SCE20429, respectively. The RAPD and SCAR markers were developed successfully to identify NCLB resistant genotypes in segregating
progenies carrying NCLB resistant traits. Thus, the markers identified in this study should be applicable for MAS for the
NCLB resistance in waxy corn breeding programs. 相似文献
13.
P. Lu J. G. Shannon D. A. Sleper H. T. Nguyen S. R. Cianzio P. R. Arelli 《Euphytica》2006,149(3):259-265
Soybean Cyst nematode (SCN) Heterodera glycines Ichinohe is the most serious pest of soybean [Glycine max (L.) Merr.] in the world and genetic resistance in soybean cultivars have been the most effective means of control. Nematode populations, however, are variable and have adapted to reproduce on resistant cultivars over time due mainly to the narrow genetic base of SCN resistance in G. max. The majority of the resistant cultivars trace to two soybean accessions. It is hoped that new sources of resistance might provide durable resistance. Soybean plant introductions PI 467312 and PI 507354, are unique because they provide resistance to several nematode populations, i.e. SCN HG types 0, 2.7, and 1.3.6.7 (corresponding to races 3, 5, and 14) and HG types 2.5.7, 0, and 2.7 (corresponding to races 1, 3, and 5), respectively. The genetic basis of SCN resistance in these PIs is not yet known. We have investigated the inheritance of resistance to SCN HG types 0, 2.7, and 1.3.6.7 (races 3, 5, and14) in PI467312 and the SCN resistance to SCN HG types 2.5.7 and 2.7 (races 1 and 5) in PI 507354. PI 467312 was crossed to ‘Marcus’, a susceptible cultivar to generate F1 hybrids, 196 random F2 individuals, and 196 F2:3 families (designated as Pop 467). PI 507354 and the cultivar Hutcheson, susceptible to all known SCN races, were crossed to generate F1 hybrids, 225 random F2 individuals and 225 F2:3 families (designated as Pop 507). The F2:3 families from each cross were evaluated for responses to the specific SCN HG types in the greenhouse. Chi-square (χ2) analyses showed resistance from PI 467312 to HG types 2.7, and 1.3.6.7 (races 5 and 14) in Pop 467 were conditioned by one dominant and two recessive genes (Rhg rhg rhg) and resistance to HG type 0 (race 3) was controlled by three recessive genes (rhg rhg rhg). The 225 F2:3 progenies in Pop 507 showed a segregation of 2:223 (R:S) for response to both HG types 2.5.7 and 2.7 (corresponding to races 1 and 5). The Chi-square analysis showed SCN resistance from PI 507354 fit a one dominant and 3 recessive gene model (Rhg rhg rhg rhg). This information will be useful to soybean breeders who use these sources to develop SCN resistant cultivars. The complex inheritance patterns determined for the two PIs are similar to the three and four gene models for other SCN resistance sources known to date. 相似文献
14.
Summary Fruit rot in bell pepper caused by Phytopthora capsici
Leon. is a limiting factor in its commercial production. Crosses were made between Waxy Globe, a small fruited hot type, resistant to fruit rot and four highly susceptible bell pepper commercial cultivars (Chinese Giant, California Wonder, Osh, Kosh and Yolo Wonder). Studies of the F1's, F2's and backcrosses indicated that Waxy Globe carries a dominant gene imparting resistance to fruit rot. After three backcrosses with California Wonder, lines were obtained combining the resistance gene of Waxy Globe with the large fruit size and low capsaicin of California Wonder. 相似文献
15.
Summary Angular leaf spot (Isariopsis griseola
Sacc.) is a serious disease of French bean in the hills of India and 40 to 70 per cent of the green pods are damaged and rendered unmarketable. Crosses were made between PLB 257, (Phaseolus coccineus L.), a red flowering pole tope, resistant to angular leaf spot, and Contender (Phaseolus vulgaris L.), a highly susceptible commercial cultivar. Studies of the F1, F2, and F3 progenies indicated that PLB 257, carries a recessive gene imparting resistance to angular leaf spot. 相似文献
16.
Downy mildew, incited by Peronospora parasitica (Pers.: Fr.) Fr., is a destructive disease of broccoli (Brassica oleraceaL., Italica Group). Resistant cultivars represent a desirable control method to provide a practical, environmentally benign,
and long-term means of limiting damage from this disease. Doubled-haploid (DH) lines developed by us exhibit a high level
of downy mildew resistance at the cotyledon stage. To determine the mode of inheritance for this resistance, a resistant DH
line was crossed to a susceptible DH line to make an F1, from which F2 and backcross (BC) populations were developed. All populations were evaluated for response to artificial inoculation with
P. parasitica at the cotyledon stage. All F1 plants (including reciprocals) were as resistant as the resistant parent, indicating no maternal effect for this trait. F2 populations segregated approximately 3resistant to 1 susceptible, BC populations using the resistant parent as the recurrent
parent contained all resistant plants, and the BC to the susceptible parent segregated 1 resistant to 1 susceptible. These
results indicate that resistance is controlled by a single dominant gene. This gene should be easily incorporated into F1 hybrids and used commercially to prevent downy mildew at the cotyledon stage.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
17.
Summary Cucumber (Cucumis sativus) lines resistant to angular leafspot caused by Pseudomonas lachrymans react to an infection by developing necrotic lesions that lack the chlorotic halo characteristic of the susceptible reaction. The inheritance of the non-halo lesion reaction was studied in all possible crosses between resistant lines MSU 9402 and Gy 14A, and susceptible cultivars Wisc. SMR 18 and National Pickling. Genetic analysis of the F1, F2, backcross and F3 populations revealed that the non-halo lesion type, associated with resistance, was controlled by a single recessive gene, pl. This character appears to be an important component of resistance to P. lachrymans. 相似文献
18.
Summary Two blue-mold resistant cultivars of Nicotiana tabacum L. were crossed with each other and with the susceptible Israeli local cultivar Mikhal. F1, F2 and F3 progenies of these crosses, F1 and F2 of backcrosses and the parental varieties were grown in a series of experiments, in which the seedlings were exposed to heavy natural infection with Peronospora tabacina Adam. The genetic basis of resistance was found to be identical in the two resistant strains Bel-61-10 and Chemical mutant. A single dominant major gene determined the segregation of resistance versus susceptibility in the crosses of these strains with Mikhal. The level of resistance of resistant segregates was shifted by environment and by quantitatively modifying genes. The index of resistance, which was calculated as a weighted mean of the degree of blue-mold expression of the resistant segregates, differed in the generations of cross progeny. This could be explained by the different expected levels of the modifying genes in these generations. Heritability of the index of resistance was calculated by parent-offspring regression and it was found to be 0.542 in the F3 and 0.227 in F2 backcross progenies. 相似文献
19.
Summary The inheritance of field resistance to downy mildew in lettuce derived from cv. Grand Rapids was studied in F2, F3 and F4 progeny from a cross with the more susceptible cv. Lobjoits Green Cos. The results for 32 randomly produced F3 families and the F2 population corresponded closely although the absolute level of resistance varied from season to season according to disease pressure and environmental conditions. The field resistance character showed a quantitative pattern of inheritance but the rapid response to selection at F3 implied that only a few genes may be involved. F4 families raised from families selected from the two extremes of the F3 distribution fell into distinct categories with resistance levels corresponding to that of their F3 parents. An association between resistance and morphological features of the resistant parent was present at F2 but not in subsequent generations when individuals and families which were as resistant as cv. Grand Rapids and yet bore little morphological resemblance to this cultivar were readily recovered. 相似文献
20.
A series of half-diallel crosses involving early, medium and late maturity desi and kabuli type chickpea (Cicer arietinum L.) genotypes with stable resistance to Helicoverpa pod borer, along with the parents, were evaluated at two locations in India to understand the inheritance of pod borer resistance
and grain yield. Inheritance of resistance to pod borer and grain yield was different in desi and kabuli types. In desi type chickpea, the additive component of genetic variance was important in early maturity and dominance component was predominant
in medium maturity group, while in the late maturity group, additive as well as dominance components were equally important
in the inheritance of pod borer resistance. Both dominant and recessive genes conferring pod borer resistance seemed equally
frequent in the desi type parental lines of medium maturity group. However, dominant genes were in overall excess in the parents of early and
late maturity groups. In the kabuli medium maturity group, parents appeared to be genetically similar, possibly due to dispersion of genes conferring pod borer
resistance and susceptibility, while their F1s were significantly different for pod borer damage. The association of genes conferring pod borer resistance and susceptibility
in the parents could be attributed to the similarity of parents as well as their F1s for pod borer damage in kabuli early and late maturity groups. Grain yield was predominantly under the control of dominant gene action irrespective of the
maturity groups in desi chickpea. In all the maturity groups, dominant and recessive genes were in equal frequency among the desi parental lines. Dominant genes, which tend to increase or decrease grain yield are more or less present in equal frequency
in parents of the early maturity group, while in medium and late maturity groups, they were comparatively in unequal frequency
in desi type. Unlike in desi chickpea, differential patterns of genetic components were observed in kabuli chickpea. While the dominant genetic component was important in early and late maturity group, additive gene action was involved
in the inheritance of grain yield in medium duration group in kabuli chickpea. The dominant and recessive genes controlling grain yield are asymmetrically distributed in early and medium maturity
groups in kabuli chickpea. The implications of the inheritance pattern of pod borer resistance and grain yield are discussed in the context
of strategies to enhance pod borer resistance and grain yield in desi and kabuli chickpea cultivars. 相似文献