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1.
Successful isolation of haploids (2n=2x=24) from 4x(2EBN) Mexican species was achieved by using Modified Wenzel (MW) and Nitsch and Nitsch (NN) media for anther culture. Both media, MW and NN, gave consistent regeneration of plantlets from 4x(2EBN) Mexican species, and responses to the media were both species and accession (PI) specific. Plantlets regenerated directly from microspores, by-passing the callus cycle, were mostly haploid (2n=2x=24). Haploid plants appeared smaller and weaker than their parents with a drastic reduction in both male and female fertility. Abnormalities observed during meiosis and the lack of success in crossing confirmed the effect of the meiotic irregularities observed in the haploids. A total of 290 seeds was obtained from the 4x × 2x crosses of 4x Mexican species with irradiated pollen of 2xS. cardiophyllum and 2xS. chancayense; however, no haploid (2n=2x=24) plants resulted. Extraction of haploids from colchicinedoubled 4x (2EBN) or natural 6x(4EBN) Mexican species using a Phureja pollinator was examined to provide clues to the potential of using 2x (1EBN) pollinators for haploid induction in 4x(2EBN) × 2x(1EBN) crosses.  相似文献   

2.
Wild potato species contain many traits of economic importance. Late blight (LB) resistance and cold chipping are traits desired in potato cultivars. These traits could be co-currently introgressed if they occurred together in wild potato species. Our research objectives were (1) to determine if variation for cold chipping exists between potato species, accessions within species, and plants within accessions all having foliar LB resistance, and (2) to identify wild potato genotypes combining LB resistance and cold chipping. Materials include 665 genotypes from 43 LB-resistant accessions of 12 potato species having Endosperm Balance Numbers (EBN) of 1, 2, and 4, and 59 LB-resistant genotypes retained from these accessions for breeding. Potato chips were made from greenhouse-grown tubers following storage at 4 C for 6 months. Chip color was scored 1–10, ≤ 4 is acceptable by industry standards. Most of the variation for chip color was due to differences between species. Species ranged in the percentage of acceptably chipping genotypes (0% – 67%) with nine of 12 species having cold-chipping genotypes. Appreciable variation was present within accessions as well. The best chipping accessions wereS. verrucosum plant introduction (PI) 161173 – 4.33 / 0.67 (mean / proportion acceptable genotypes),S. stoloniferum PI 250510 -4.36 / 0.64,S. pinnatisectum PI 347766 -4.65 / 0.35 and 275233 -4.73 / 0.44, andS. megistacrolobum PI 195210 -5.14 / 0.29. Eleven 1EBN genotypes fromS. pinnatisectum andS. trifidum and five 2EBN genotypes fromS. verrucosum, S. fendleri,S. stoloniferum, andS. microdontum were identified that combined LB resistance and cold chipping. Co-current introgression would require fewer breeding cycles than other breeding methods to identify hybrid genotypes possessing both traits.  相似文献   

3.
Hexaploid somatic hybrids have been obtained by fusion of protoplasts fromSolanum brevidens (PI 218228, 2x = 2n = 24) andS. tuberosum (PI 203900 or cv. Russet Burbank; 2x = 4n = 48). In the work reported here, pentaploid progeny derived from sexual crosses between the somatic hybrids and the potato cultivar, Katahdin were assessed for transfer of disease resistances and improvement of agronomic traits. Segregation was noted in disease resistances to race 0 ofPhytophthora infestans and to tuber soft rot caused byErwinia spp., indicating that sexual transfer of traits captured by protoplast fusion had occurred. The pentaploid progeny showed substantial variation in and often improvement of some agronomic traits as compared to the somatic hybrids. The results indicate that interspecific somatic hybridization can produce material with potential for use in a potato breeding program  相似文献   

4.
Potato was domesticated in the Andes of South America. However, the presently worldwide-grown potato (Solanum tuberosum L. ssp.tuberosum, 2n=4x=48) has characteristic T-type chloroplast DNA that was introduced after late blight epidemics in the mid-19th century from the Chilean potato (2n=4x=48) grown in the southern coastal regions in Chile. Among many wild potato species, the same chloroplast DNA was found only in some populations of a diploid speciesS. tarijense Hawkes (2n=2x=24), which ranges from central Bolivia to northwest Argentina. To elucidate an evolutionary pathway of T-type chloroplast DNA fromS. tarijense to Chilean potato, 215 accessions ofS. stenotomum Juz. et Buk., considered to be the most primitive, diploid cultivated potato species, from which all the Andean cultivated species evolved, and 286 accessions of the most widely grown, Andean tetraploid cultivated speciesS. tuberosum L. ssp.andigena Hawkes (2n=4x=48) were examined in this study. No accession ofS. stenotomum had T-type chloroplast DNA, while nine accessions, mostly from northwest Argentina, ofS. tuberosum ssp.andigena had T-type chloroplast DNA. Therefore, I conclude that some populations ofS. tarijense having T-type chloroplast DNA were naturally crossed as female withS. tuberosum ssp.andigena from which the Chilean potato was selected.  相似文献   

5.
Hybrids (2n = 2x = 24) from crosses between Group Tuberosum haploids (2n = 2x = 24) and 24-chromosome, wild species must be fertile and produce 2n gametes if they are to be used in breeding schemes involving sexual polyploidization. Male fertility of the 2x hybrids depends primarily on the species parent. Hybrids involvingS. berthaultii, S. chacoense, S. kurtzianum, S. spegazzinii, andS. tarijense as parents are male fertile. The haploid parents are male sterile, so the species not only contribute genetic diversity and desirable traits, but also genes necessary for male fertility.S. infundibuliforme, S. raphanifolium, andS. sanctae-rosae parents produced male sterile hybrid progeny, while use ofS. boliviense, S. bukasovii, S. canasense, S. microdontum, andS. sparsipilum results in families containing both fertile and sterile plants. Sterility may be due to interactions between Tuberosum cytoplasm and dominant nuclear genes from the species. Genetic male sterility and environmental conditions may also be responsible for low pollen stainability in some hybrids. Many fertile, 2x hybrids produce 2n pollen. Selection for 2n pollen in the species is fast and efficient, but meiotic analysis is required in male sterile haploids. Fortunately, selection in the species parent alone results in a large number of 2n pollen-producing hybrids. These 2x hybrids have been used to generate tetraploids via 4x × 2x crosses.  相似文献   

6.
Diploid wild potato species, classified as 1EBN (Endosperm Balance Number), do not cross with tetraploid or diploid forms ofS. tuberosum Gp. Tuberosum. The crossing of 2n pollen producing 1EBN clones as well as chromosome-doubled 1EBN clones with Gp. Tuberosum haploids was initiated to overcome this hybridization barrier. The screening of eleven 1EBN species,S. brachistotrichum, S. bulbocastanum, S. cardiophyllum, S. chancayense, S. commersonii, S. etuberosum, S. fernandezianum, S. jamesii, S. mochicense, S. pinnatisectum andS. trifidum, resulted in the identification of 2n pollen producers in eight of the species examined. Direct hybridization with Gp. Tuberosum haploids utilizing the above-mentioned crossing scheme was successful withS. chancayense andS. commersonii. The hybrids obtained, however, were male and female sterile. Abnormal microsporogenesis in the hybrids was postulated to be the result of an interaction between Gp. Tuberosum cytoplasm and nuclear genes contributed by the 1EBN male parent. Analyses of the growth of 1EBN species’ pollen tubes in the stigma/style of Gp. Tuberosum haploids were also conducted. Interspecific incompatibilities were observed with the most severe forms found with the use of species in the Series Etuberosa. The use of the Endosperm Balance Number theory can aid in designing crosses which overcome barriers to successful endosperm development. Sterilities in the hybrids obtained as well as interspecific incompatibilities will also need to be addressed, however, before 1EBN species germplasm can be successfully utilized for the improvement of the cultivated potato.  相似文献   

7.
A total of 258 Plant Introductions (PI) belonging to 69Solarium species were evaluated in the greenhouse for their reaction to the tobacco veinal necrosis strain of potato virus Y (PVY N). One hundred and thirty-one (50.7%) of the PI accessions produced mosaic symptoms ranging from mild to severe. Local lesion and veinal necrosis symptoms were observed in 19 PI accessions (7.3%) and a variety of other symptoms were observed in another 11 PI accessions (4.2%). Only 97 PI accessions (37.5%) were symptomless carriers of PVYN. PI accession 473505 ofS. sparsipilum and PI accession 498021 ofS. brachycarpum developed local lesions and veinal necrosis with PVYN, but necrotic spots and mosaic with PVYo. Common mechanically-transmitted potato viruses A, S, M, and X did not interfere with PVY symptom development inS. sparsipilum andS. brachycarpum. Thus, PI 473505 and PI 498021 can be used as indicator plants for specific identification of PVYN. PI accession 472819 ofS. chacoense developed local lesions with systemic spread in PVYo, but without systemic spread in PVYN. Thus, this can be used as a differential host plant for PVY strains. Two PI accessions ofS. stoloniferum, PI 160372 and 161171 were immune to PVYN.  相似文献   

8.
The degree of enzymatic browning in tubers was examined quantitatively in five plant introduction (PI) accessions ofSolanum hjertingii and in hybrids of this species with cultivated diploids that had high enzymatic browning. Polyphenol oxidase activity and melanin formation inS. hjertingii accessions was subjected to an analysis of variance. There was significant variation in melanin formation within accessions but the between accession component was not significant. This indicates that it would be most advantageous to select low melanin formation by evaluating individual genotypes within an accession. Significant variation for PPO activity existed between accessions, indicating that selection on the basis of accession means would be the best means of selecting for lower PPO activity. Both parameters were much lower in allS. hjertingii genotypes compared to tetraploid cultivars known for their susceptibility to internal blackspot when mechanically damaged. The reduced browning inS. hjertingii was due to a lack of PPO activity and not the shortage of substrate. Progenies, and parents of four crosses between selectedS. hjertingii genotypes and cultivated diploids were measured for PPO activity and melanin formation. The mean performance of the progenies was closest to theS. hjertingii parent in all cases. Degree of dominance indicated nearly complete dominance or overdominance in the direction of theS. hjertingii parent. These results are discussed in light of other work which indicates that protein antigenic to PPO antibody is present inS. hjertingii. It appears that inactive PPO is present in the tubers. The pronounced dominance of low PPO activity and suppression of melanin formation in the hybrids withS. hjertingii is promising for the utility of this wild species as a source of genetic factors that, upon introgression into the cultivated potato gene pool, would suppress browning.  相似文献   

9.
The recent US-8 clonal lineage ofPhytophthora infestans, the pathogen causing late blight (LB) disease, is one of the most widespread and difficult to control. Sources of foliar resistance to US-8 were evaluated in 1927 seedling genotypes by sampling 49 plant introductions (PIs) representing 13 Mexican and South AmericanSolanum species having an Endosperm Balance Number (EBN) of 1, 2, or 4, and one species with an unknown EBN. Species evaluated were 2x(1EBN)S. bulbocastanum, S. cardiophyllum, S. commersonii, S. pinnatisectum, andS. trifidum; 2x(2EBN)S. berthaultii, S. megistacrolobum, S. microdontum, andS. verrucosum; 4x(2EBN)S. fendleri andS. stoloniferum; 6x(4EBN)S. guerreroense;2x unknown EBNS. polyadenium; as well as4x S. tuberosum families as controls. Foliar resistance in the field was monitored in 1998 and 1999. Resistance differed relative to species geographic origin, EBN, species themselves, PIs within a species, and genotypes within a PI. In 1998 Mexican germplasm had a lower area under the disease progress curve (AUDPC, 1140) and greater resistance than South American germplasm (1601), while the 1EBN (1119) and unknown EBN (1075) species had greater resistance than 2EBN (1470) and 4EBN (1888) species. AUDPC ranged among species from 555 (S. cardiophyllum) to 1932 (S. megistacrolobum) and among PIs within a species most widely forS. bulbocastanum (267–1007) and least widely forS.polyadenium (1019–1179). In 1999 LB symptoms were not observed on the species before an early freeze; however, all 1999S. tuberosum families showed LB symptoms and segregated for resistance, pointing to greater resistance in the species than in cultivated germplasm. Resistance found in diploid 2EBN germplasm is more accessible due to greater crossability with cultivated germplasm; however, though more difficult to introgress, resistance found in some of the more reproductively isolated 1EBN germplasm is worth pursuing.  相似文献   

10.
Wild potato species possess genetic variability for valuable traits including resistance toPhytophthora infestans, the causal agent for potato late blight disease. Breeding schemes using 2n gametes are a powerful tool for introgressing these traits. Forty-five plant introductions (PIs) across 12Solanum species representing various Endosperm Balance Numbers (EBN) and having resistance toP. infestans (US-8, isolate ND 95-2) were screened for 2n pollen production and male fertility. Species evaluated were 2x(lEBN)S. bulbocastanum, S. cardiophyllum, S. pinnatisectum, andS. trifidum; 2x(2EBN)S. berthaultii, S. megistacrolobum, S. microdontum, andS. verrucosum; 4x(2EBN)S. fendleri andS. stoloniferum; 6x(4EBN)S. guerreroense; and 2x(unknown EBN)S. polyadenium. Acetocarmine staining and cytological analyses were used to determine 2n pollen production and pollen stainability from genotypes grown across three locations. Based on frequency, genotypes were assigned to 2n pollen production categories (0≤1%, Low=1%–10%, Medium=11%–60%, and High≥60%) and pollen stainability categories (0≤1%, 1=196–5%, 2=6%–10%, 3=11%–20%, 4=21%–50%, and 5≥50%). Eleven of the 12 species and 37 of the 45 PIs examined contained genotypes producing ≥1% 2n pollen with ranges of 0%–63.6% and 0%–81.8%, respectively. Dependence was found between location and pollen stainability, EBN and pollen stainability, but not for location and frequency of genotypes with 2n pollen. Stability for 2n pollen production was observed across environments. Among the 1EBN germplasm, dependence was found between 2n pollen and pollen stainability. Resistance toP. infestans was found to be independent of 2n pollen production; therefore, identifying genotypes combining 2n pollen production, fertility, and resistance toP. infestans was possible.  相似文献   

11.
A clone, 8380-1, selected fromSolanum chacoense (PI 458310) for its high foliage content of the leptine glycoalkaloids, a factor in resistance to Colorado potato beetle, was doubled in chromosome number from 2n=2x=24 to 2n=4x=48. Three 4x clones were crossed with sixS. tuberosum (4x) clones. Foliage glycoalkaloid contents were measured for 452 F1 hybrids from 15 crosses. The 4xchacoense parental clones were not different in respect to glycoalkaloid contents and were similar to the original 2x clone. All F1 hybrids synthesized foliage leptines ranging from 9 to 369 mg/100 g fresh weight (fw) with a mean content of 113 mg/100 g fw. The proportion of leptines in the total glycoalkaloid content ranged from 1% to 62% with a mean of 25%. The 4xchacoense parent mean leptine content was 1482 mg/ 100 g fw which was 90% of the total glycoalkaloid content. Tubers from 136 hybrids and the threechacoense parental clones were tested for glycoalkaloid contents. The tuber solanine + chaconine contents of the 136 hybrids ranged from 30 to 180 mg/100 g fw with a mean of 79. The mean tuber content of the threechacoense parental clones was 157 mg/100 g fw. Leptines were not found in any of the tubers.  相似文献   

12.
Haploids (tetraploids and triploids) were obtained from crosses between colchicine-doubled octaploid and natural hexaploid Mexican potato species and the Gp. Phureja clone 1.22 as the pollinator, but none were obtained from crosses of natural 4x(2EBN) Mexican species with 2x(1EBN) pollinators. The manipulation of ploidy and Endosperm Balance Number (EBN) of tetraploid Mexican potato species was useful in explaining the occurrence of pseudogamous parthenogenetic haploid production. The pollinator effect, EBN, and maternal influence are important characters to consider in searching for haploid-inducing pollinators among 2x(2EBN) as well as 2x(1EBN) potato species.  相似文献   

13.
Development of potato cultivars resistant to Erwinia species (Erwinia carotovora subspeciesatroseptica, E. carotovora subspeciescarotovora, andErwinia chrysanthemi) causing soft rot of stems and tubers involves identification and transfer of the resistance to breeding lines possessing desirable agronomic traits. In total, 363 accessions of six wildSolanum species, three somatic hybrids and nine sexual progeny of somatic hybrids were screened for stem soft rot resistance. Thirty-one, 50, and 67 percent of accessions ofSolanum boliviense, Solanum chacoense, and Solanumsanctarosae, respectively, were resistant or highly resistant, whereas, 100, 97, and 95 percent of accessions ofSolanum canasense, Solanum tarijense, andSolanum spegazzinii were susceptible or highly susceptible, respectively. Two tuber soft-rot resistant somatic hybrids, A937 and T355-11 produced earlier by the fusion ofSolanum brevidens (PI 218228) andSolanum tuberosum (PI203900) orS. tuberosum cv. Russet Burbank, respectively, and the sexual progeny of A937 andS. tuberosum cv. Katahdin were also highly resistant. Transfer of resistance fromS. brevidens to somatic hybrid (A937) and subsequently to the progeny suggests that the resistance is simply inherited. In addition to the identification of 65 resistant or highly resistant clones of wildSolanum species, this study has identified three tuber soft rot-resistant clones that are also resistant to stem soft rot. Potato cultivars showed a range of responses to the pathogen.  相似文献   

14.
Twelve accessions ofSolarium fendleri collected in the United States and Mexico were inoculated with 5,000 eggs of host-races 1 and 2 ofMeloidogyne chitwoodi, Columbia root-knot nematode. The test seedlings that were derived from plant introduction true seed lots were maintained for 55 days before harvest and egg count. The results revealed that two accessions, PI 275162 and PI 275165, were non-hosts (final egg count/initial egg inoculation < 0.1) forM. chitwoodi race 1. The results were uniformly confirmed in the second experiment. No resistance was found to race 2. The tetraploidS. fendleri accessions were crossed to a nematode-susceptible cultivated diploid potato clone from aS. phurejastenotomum population. The triploid hybrids expressed resistance to race 1 at the non-host level. After somatic doubling, the resulting hexaploids also expressed non-host-level resistance to race 1. The two resistant accessions had been collected in southeastern Arizona, one each from the Huachuca and Chiricahua Mountains. Each range is an isolated island of high-elevation mesic flora surrounded by typical lowerelevation Sonora-type desert habitat. These accessions are the only known sources of resistance toM. chitwoodi from wildSolanum species in the USA.  相似文献   

15.
Peru contains about half of the described wild potato taxa, and many of these are not yet preserved in genebanks. This paper reports results of the second of a series of five planned collecting expeditions to Peru. Collections were made in the central Peruvian departments of Ancash, Huancavelica, La Libertad, and Lima, from March 8 to April 25,1999. They follow collections in 1998 in the southern Peruvian departments of Apurimac, Arequipa, Cusco, Moquegua, Puno, and Tacna. We collected 101 germplasm accessions, including first germplasm collections of the following 22Solanum taxa:Solanum amayanum, S. anamatophilum, S. arahuayum (lost in germplasm increase),S. augustii, S. bill- hookeri, S. cantense, S. chavinense, S. chomatophilum var. subnivale, S. chrysoflorum, S. gracilifrons, S. hapalos um, S. huarochiriense, S. hypacrarthrum, S.jalcae, S. moniliforme, S. multiinterruptum f. longipilosum, S. multiinterruptum var. machaytambinum, S. peloquinianum, S. rhombilanceolatum, S. simplicissimum, S. taulisense (lost in germplasm increase), andS. wittmackii. In addition, new collections were made of the under-collected speciesS. hastiforme (three collections). The above taxonomy is that used in planning our expedition, that we compare to a new treatment of Peruvian wild potatoes published by C. Ochoa in 1999. This paper reports the collection and new species identifications of the 1999 collections, and germplasm conservation and survival of the 1998 and 1999 collections. In addition, chromosome counts are provided for 134 accessions from the 1998 and 1999 expeditions, including first reports forS. chomatophilum var. subnivale (2n = 2x = 24),S. megistacrolobum subsp.purpureum (2n = 2x = 24), andS. multiinterruptum var.multiinterruptum f.albiflorum (2n = 2x = 24); we also report the first triploid count of an accession ofS. immite.  相似文献   

16.
Protoplasts were fused to produce somatic hybrids between a triploid (2n=3x=32-34) interspecific somatohaploid betweenSolanum brevidens Phil. andS. tuberosum L., and a dihaploid (2n=2x=24) anther-derived line ofS. tuberosum cv. Van Gogh. A total of 265 plants were regenerated from protoplast fusion derived calli and their hybridity was verified using fusion partner specific RAPD markers. These “second generation” somatic hybrids were aneuploid pentaploids (2n=5x=51-65) with a 2C DNA content ranging from 3.36 to 4.43 pg, which corresponded to the sum of the 2C values of each of the fusion partners (somatohaploid: 2.22 pg; and the dihaploid line of cv. Van Gogh: 1.87 pg). Most of the “second generation” somatic hybrids were vigorous, but variable in morphology. They were extremely resistant to PLRV and they had tolerance to PVY infection derived from the somatohaploid fusion partner. Even though most of the “second generation” hybrids tuberized, the tuber morphology was variable and most were poorly shaped. InErwinia soft rot resistance tests, the tubers showed higher level of resistance than the tetraploidS. tuberosum cultivars, the dihaploidS. tuberosum fusion partners and the hexaploid somatic hybrids betweenS. brevidens andS. tuberosum. The “second generation” somatic hybrids were all male sterile and failed to produce berries or seeds.  相似文献   

17.
Fifty-nine clones (cultivars and advanced selections) ofSolanum tuberosum Group Tuberosum were pollinated with two Group Phureja-haploid Tuberosum hybrids, which produce FDR 2n pollen (ps/ps) and are heterozygous for a dominant gene (Ms/ms) which interacts with Tuberosum cytoplasm to result in male sterility. Twenty-eight and thirty-four plants from each family were transplanted to the field in two different locations, respectively. Pollen samples were collected from each plant and stained with acetocarmine glycerol jelly. Plants with over 95% unstainable pollen were considered male sterile. The families could be put into distinct classes according to the ratio of male sterile to male fertile plants; 3 sterile: 1 fertile (23 clones), 2 sterile: 3 fertile (24 clones), 1 sterile: 5 fertile (3 clones), and 0 sterile: 1 fertile (3 clones). Four families deviated significantly from any expected ratio. The variation for male fertility among families resides in the tetraploid parent, since the male parents have the same genotype (Ms/ms) for theMs locus. The locus of this gene is very distal to the centromere such the 2n gametic output is 1 Ms/Ms : 2 Ms/ms : 1 ms/ms. The variation in male sterility is explained by the presence or absence of a dominant allele of a restorer gene (Rt) in tetraploid Tuberosum. This locus is also very distal to the centromere. The frequency of theRt gene was estimated to be 0.20 in Tuberosum. The finding ofRt gene explains some of the conflicting results in male fertility of haploid Tuberosum x 2x cultivated and wild species hybrids. It also provides an opportunity to partially circumvent this male sterility. Haploids (2n = 2x = 24) extracted from 4x clones withRt genes would have male fertile progeny in crosses with species carrying theMs gene.  相似文献   

18.
Summary Solanum xedinense Berth., a pentaploid (2n=5x=60) interspecific hybrid between the cultivated potato and the wild speciesSolanum demissum Lindl., represents evidence of genetic exchange between wild and cultivated species. It has been found in Central Mexico at altitudes between 2000 and 3500 meters, growing in and along the edges of cultivated fields, roadside thickets, forest margins and along irrigation ditches. This study examined the hybrid nature of S.xedinense using molecular, cytological and crossability data. RAPD and AFLP markers were used to supportS. xedinense as a hybrid between the cultivated potato andS. demissum. Meiotic analysis and crossability studies were used to examine the potential ofS. xedinense to form offspring. Several accessions ofS. tuberosum L. subsp.tuberosum and subsp.andigena Hawkes,S. demissum and an accession ofS. xedinense were used in the study. Artificial hybrids betweenS. tuberosum subsp.tuberosum andS. demissum were included for comparison. Molecular analysis positioned the natural and artificial hybrids as an intermediate group between the parental populations, supporting their relationship with the parental populations. Meiosis was abnormal in both natural and artificial hybrids, and reduced crossability was noted forS. xedinense. Although gene flow appears to happen between wild and cultivated potato, the potential for the natural hybrids to become established may depend mostly on their ability to clonally propagate themselves.  相似文献   

19.
Diploid potato clones, interspecific hybrids ofSolanum species, having in their originS. tuberosum,S. chacoense, S. yungasense, S. phureja, S. gourlayi, andS. demissum, with resistance to soft rot, were crossed to tetraploid potato clones in 4x-2x crosses. The 24 tetraploid families obtained in a North Carolina II design were examined for tuber resistance to soft rot in a laboratory test and for basic agronomic traits in field trials conducted for two consecutive years. In addition, one family originating from a 4x-2x cross of two susceptible parents was tested. Statistical analysis of the data revealed significant general (GCA) and specific combining ability (SCA) effects, year, GCA (female) × year, GCA (male) × year, and SCA × year upon the inheritance of resistance to soft rot. About 35% of the progeny was selected as resistant to tuber soft rot, and of these 11% showed high resistance combined with good tuber yield, tuber weight, and tuber appearance. The relationships between resistance to soft rot and chosen agronomic traits were not noted or were weakly significant and sporadic. The resistance to tuber soft rot found in diploid potato hybrids can be transferred to the cultivated tetraploid pool through 4x-2x crosses, and a high frequency of offspring posses resistance.  相似文献   

20.
多效唑对晋薯7号马铃薯的调控作用   总被引：4，自引：2，他引：2  
在马铃薯初花期喷施植物生长调节剂多效唑,试验结果表明:多效唑显著抑制植株的高度,单株结薯数下降,大薯率上升,当每667m2喷施多效唑75g,浓度在2.5g.L-1时是本试验中提高产量的最佳浓度,干物质和淀粉均有明显的提高。说明喷施多效唑具有控上促下的作用,从而有利于提高产量和品质。  相似文献   

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