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1.
Two thousand and fifty-five pollinations were made between the cultivar Russet Burbank and Group Phureja pollinator clone 1.22, resulting in 882 fruit and 253 seeds. One-hundred and fifty progeny grew from these seeds, of which 6 were haploids, 143 were triploids and 1 was tetraploid. None of the haploids flowered. The predominance of triploids was unusual for Gp. Tuberosum cultivars, but it does not indicate a breakdown of the “triploid block” because of the low seed set. These results are similar to those found during haploid extraction from Gp. Andigena, suggesting the possibility that Gp. Andigena may have been involved in the parentage of Russet Burbank.  相似文献   

2.
The types of reciprocal differences found in higher plants are generally limited to those characters which are controlled by one or two major genes. There are, however, a few examples where the progeny from reciprocal crosses differ in yield or other quantitative characters. Both have been ascribed mainly to cytoplasmic inheritance. In cultivated tetraploid potatoes (Solatium tuberosum Group Tuberosum) differences in yield of the progeny from reciprocal crosses have been found. These reciprocal differences are attributed to the mode of 2n gamete formation rather than cytoplasmic differences. Preliminary experiments involving reciprocal crosses between Tuberosum cultivars (2n=4x=48) and Phurejahaploid Tuberosum hybrids (2n=2x=24) indicated that some progenies from 4x x 2x crosses yield more than progenies from reciprocal crosses. It was hypothesized that the differences in tuber yield may be due to one or more of the following factors: (i) the effect of high fruit set on yield —i.e. almost 100% of the progenies from 2x X 4x crosses are male fertile and thus higher fruit set is expected than in the 4x X 2x progenies where only about 57% of the F1 clones are male fertile; (ii) the advantage of being in 4x cytoplasm if the nucleus is 4x; and (iii) the difference in mode of 2n gamete formation-first division restitution (FDR) gives highly heterozygous gametes and second division restitution (SDR) results in highly homozygous gametes. Six families of reciprocal crosses between three 4x cultivars (Merrimack, Superior, and Wis 639) and three 2x Phureja-haploid clones (W5293.3, W5295.7, and W5845.1) were planted in 1970 in Rhinelander in a split-plot design with two tubers of each clone in each of two replicates. Flowers were removed from one of the paired plants in each family. Even though the fruit yields were higher in 2x X 4x progenies as expected, tuber yields were not affected by fruit formation. Therefore, factor (i) is apparently not involved in the reciprocal differences observed. Significantly higher tuber yields were obtained from 4x X 2x families only with the 2x clone W5295.7. This eliminated factor (ii), since no difference in reciprocals was obtained with the other 2x clones. Factor (iii) could thus be responsible for differences in reciprocal crosses, since cytological observations indicate only W5295.7 of the 2x clones used forms 2n pollen by FDR.  相似文献   

3.
Potato germplasm with high levels of combined resistance to potato viruses X, Y, and leafroll was identified and used to produce improved parental clones with similarly high levels of resistance. Resistance was determined from the amount of tuber infection following inoculation of plants in the field. Parental germplasm with the best multiple resistance came from two backgrounds, eitherSolanum tuberosum group Andigena derived from the Cornell University neo-tuberosum program, or from complex hybrids ofS. tuberosum and wild solanums that were produced by the Max Planck Institute and the Polish Institute for Potato Research. Two Aberdeen, ID selections, A85519-6 and A85530-10, with gp. Andigena ancestry, have had no tuber-borne infection of PVX, PVY, or PLRV during four years of intensive field testing. We have not been successful in combining virus S resistance with resistance to the other viruses.  相似文献   

4.
The identification of diploid(2x), Tuberosum haploid × wild species hybrids (HS) which produce high frequencies of 2n eggs and have good tuber appearance is important for obtaining 4x progeny from 2x × 2x crosses in potato. More than 1700 HS clones were screened for the occurrence and frequency of 2n eggs through 2x × 4x crosses during two pollination periods. The resulting seed/fruit provides an estimate of 2n egg frequency. About 650 HS clones produced 2n eggs; 63 had 10–114 seeds/fruit; and 27 were selected for good tuber type. There was a large variation in seed set after 2x × 4x crosses, both within and between clones. Comparison of fruit and seed set between the two pollination periods using the same 595 clones indicated that environmental factor significandy affected 2n egg frequency. The mode of 2n egg formation was mainly due to omission of the second meiotic division controlled by a recessive gene (os). The gene frequency foros varied from 0.28 to 0.76 among six, 2x taxa. Both additive and dominance variance were significant for seed set after 2x × 4x crosses. Narrow sense heritability was estimated as 0.24. The average degree of dominance was equal to 1.66 which could indicate overdominance. Alternatively, this could be due to linkage disequilibrium,i.e. pseudooverdominance. However, dominance variance was greater than the additive variance indicating recurrent selection can be useful for improving the frequency of 2n egg production in the 2x population. The selected individuals, based on their phenotypic performance, should be progeny tested to identify the best parents for use in the next cycle of recombination.  相似文献   

5.
Gibberellins have been shown to be involved in such important processes as seed germination, flowering, maturation and tuberization in potato. Parents fromSolanum tuberosum Groups Andigena and Tuberosum were found to produce progeny containing dark green, rosette dwarf individuals which could be completely restored to normal appearance by exogenous GA3. Test crosses indicated that this phenomenon can be explained by the action of a single locus, the dwarfing characteristic being conferred by the nulliplex condition. The gene symbol “ga1” is proposed. Group Andigena dwarfs demonstrated much greater tuberization compared to their normal full sibs or dwarfs restored to normal phenotype by exogenous GA3. The possibility that such gibberellin mutants may be involved in the long day adaptation of Gp. Tuberosum is discussed. This character may also be a useful tool for investigating various aspects of the gibberellin status of the potato.  相似文献   

6.
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   

7.
The crossability of Group Andigena haploids was investigated in this study. Groups Phureja, Stenotomum and Tuberosum haploids were crossed to Gp. Andigena haploids reciprocally to estimate the female and male fertility of the latter. The male fertility of Gp. Andigena haploids was reflected by the average seed set from crosses to Gps. Phureja Stenotomum and Tuberosum haploids (69, 43 and 21 seeds per fruit, respectively); female fertility was expressed when Gps. Phureja or Stenotomum served as the male, yielding 48 and 38 seeds per fruit, respectively. To contrast Gp. Andigena and Gp. Tuberosum haploid male fertility, they were crossed among and between themselves. As males, Gp. Andigena haploids gave three to four times the seed set of Gp. Tuberosum haploids. Pollen tube growth was analyzed in various Gp. Andigena haploid crosses to determine the site of cross failure. The results presented provide the basis for the first step in determining the potential of Gp. Andigena haploids in the development of diploid breeding stocks and the 2n gamete approach to potato improvement.  相似文献   

8.
The objective of this study was to characterize sixS. commersonii - S. tuberosum progenies deriving from 5x ? 4x crosses to provide evidence that they can be used in potato breeding. Hybrids analyzed (coded PTH) had a chromosome number between the 4x and the 5x level. In particular, progeny means for chromosome number ranged from 50±0.5 to 54±0.7, with most (70%) genotypes exhibiting a low aneuploid level of 48 to 53 chromosomes. Despite being aneuploid, the hybrids did not generally show phenotypic aberrations or vigor reduction common to aneuploids of other species. Most genotypes resembledS. tuberosum in growth habit, whereas corolla type, eye depth, and stolon length varied between and within progenies. Aneuploid hybrids produced tubers under long-day conditions. However, tuber yields were not as high as expected, probably due to lack of adaptation of theS. commersonii genome to long-day conditions. Although aneuploidy has often been associated with reduced male and female fertility, many 5x ? 4x hybrids were fertile in crosses withS. tuberosum. The average berry set and number of seeds/berry were 33% and 34.7, respectively, following PTH ×S. tuberosum crosses, and 40% and 51.7, respectively, forS. tuberosum × PTH crosses. The useful variation for fertility and tuber traits found in this material is being used for further breeding efforts.  相似文献   

9.
The possibility of scaling ploidy levels up and down offers several advantages for genetic studies and breeding work in potato. Shoot regeneration and chromosome doubling in plants regenerated fromin vitro cultures were investigated in 4 diploid (2n=2x=24) and 2 triploid (2n=3x=36) clones. Internode and leaf expiants were taken from plants propagated eitherin vitro as shoot cultures, orin vivo in a greenhouse. Two regeneration procedures were compared. Regeneration frequencies were significantly higher using a two-step regeneration protocol and from leaf explants, while doubling was more efficient starting fromin vivo grown plants. No doubling was observed in triploid clones. Considering altogether the percentage of regeneration and doubling, and the number of shoots regenerated per explant, the most efficient conditions were considered leaf explants taken fromin vivo grown plants, and cultured according to a two-step regeneration protocol.  相似文献   

10.
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   

11.
Solanum tuberosum Group Tuberosum haploids (2n = 2x = 24) were inter-mated using bulk pollen. Nearly half of the resulting progeny were tetraploid, arising from bilateral sexual polyploidization. Subsequent yield trials indicated that the diploid progeny did not yield significantly more than the original haploids, but the tetraploid progeny did yield significantly more than their diploid sibs and the original haploids. Tetraploid cultivars and conventional tetraploid breeding families significantly out-yielded the haploid-derived tetraploids. These results and the theoretical considerations which are presented indicate that inter-mating haploidsper se does not increase heterozygosity. More importantly, these results indicate that without the introduction of new germplasm, haploidization followed by repolyploidization can only be expected to result in tetraploids with heterozygosity equal to or below that of their parents.  相似文献   

12.
《Field Crops Research》1988,19(3):183-200
Nine experiments were run at three hot tropical sites (5–12°S, 180–800 m) within Peru to quantify the influence of plant population on soil temperature and growth and yield of the potato.Radiation interception was greatest at the highest plant populations and soil cooling was directly proportional to the amount of crop cover over the soil, but no appreciable effect on the timing of tuber initiation was apparent. More stems per unit land area leading to a higher leaf area index (lai) were primarily responsible for greater interception of radiation at the higher plant populations, although some compensation in stem number per unit land area and in lai at lower populations was evident later in the season.In general, tuber yield increased linearly with increases in planted population over the range studied (2.7–12.5 plants m−2, and in one experiment to 31.7 plants m−2), and was proportional to increases in the amount of intercepted radiation. Tuber yields ranged from 8 to 60 t ha−1 over sites and populations. Vigorous clones with Solanum tuberosum spp. andigena in their genetic background constituted the exceptions to this linear trend, and for these clones yields declined at the highest populations, particularly when the rectangularity of planting vastly deviated from square patterns. Tuber yield of Solanum tuberosum spp. tuberosum and Neotuberosum (S. tuberosum spp. andigena selected for tuberization under long-day conditions) clones did not respond to variations in rectangularity of planting and, probably due to their small stature and early maturity, did not demonstrate signs of intense between-plant competition for tuber yield as measured with the Kira competition density index. In contrast, for clones with Solanum tuberosum ssp. andigena in their genetic background, maximum tuber yield at populations greater than 5.5 plants m−2 was dependent on the rectangularity of planting, and declined as the latter deviated from squareness.Since the proportion of marketable tubers was scarcely affected by the planting densities, plant population of S. tuberosum ssp. tuberosum clones planted in hot climates should be as close as possible without limiting the amount of soil available for hilling-up.  相似文献   

13.
The cytological basis of 2n pollen production was studied in a diploidSolanum progeny coming from a cross between aS. tuberosum S. chacoense hybrid which does not produce2n pollen (T710) and a S.phurejar S. tuberosum hybrid (W5295.7) which does. Both parental clones showed anomalous orientation of spindles at Metaphase II of microsporogenesis, but only clone W5295.7 produced dyads. All plants of the progeny T710 × W5295.7 showed anomalous spindles at Metaphase II, but only 60% of them produced 2n pollen, thus evidencing a discrepancy between spindle anomalies and dyad/2n pollen production. This may suggest that both parallel and fused spindles are a necessary but insufficient condition for 2n pollen production, and that some other mechanisms expected to be more highly correlated with them may be involved in 2n pollen production in this population.  相似文献   

14.
Potato yellow vein virus (Crinivirus) causes leaf yellowing, is limited to the phloem and is transmitted by Trialeurodes vaporariorum and tubers. PYVV causes up to 50 % yield reduction in S. tuberosum. The prevalence of PYVV was established in Group Phureja in 2008 in the Colombian states of Cundinamarca, Antioquia and Nariño. The presence (S) or absence (NS) of symptoms was established in 24,930 plants. Symptom prevalence was as follows: Cundinamarca 0.74 %?±?0.03, Antioquia 5.4 %?±?12 and Nariño 6.2 %?±?0.11. Percentages of S plants were highly variable among different states and municipalities. PYVV was diagnosed by RT-PCR in a subsample of 1,545 plants from Cundinamarca and Nariño. RT-PCR showed that 2.4 %?±?8.3?×?10?5 and 41 %?±?0.0009 % of the symptomless plants of Cundinamarca and Nariño respectively were positive. This suggests possible late infection of plants by the vector which did not have enough time to express symptoms, infections with two or more viruses or “virus latency”. PYVV symptomatic prevalence in Group Phureja was lower than that reported for Diacol-Capiro (Group Andigena), but increases if molecular results are taken into account. This is the first known study aimed at determining PYVV prevalence using molecular tools and extensively sampling of S.tuberosum Group Phureja plants in grower’s fields in three states and multiple municipalities of Colombia.  相似文献   

15.
Over 250 accessions ofSolanum phureja from Colombia and 300S. phureja—S. tuberosum hybrids were screened in the greenhouse for resistance toPseudomonas solanacearum (isolate K-60). Each plant was inoculated by stem puncture at the pre-bud stage and then held at a constant 28 C for 15 days. Seventeen clones with different levels of resistance to K-60 were inoculated with nine additional isolates representing all three races of the bacterium. The reactions of individual clones varied from resistance to almost all isolates, resistance to only one isolate, or complete susceptibility. Crosses amongS. phureja clones and betweenS. phureja and 24-chromosomeS. tuberosum stocks gave progeny with various percentages of resistant plants. Clones with resistance equal to that inS. phureja were found in theS. phureja × S. tuberosum crosses. Tests conducted in growth chambers showed that resistance was expressed more frequently at high light intensity (2000 ft-c) than at low intensities (1300 ft-c) at 24 C and 28 C. Resistance appears to be relatively simply inherited and the prospects for transferring a high level of resistance into cultivated forms are promising.  相似文献   

16.
The South American tetraploid potatoesSolanum tnberosum sspandigena have been used to increase the genetic variability of the temperate potatoS. tuberosum ssptnberosum. One technique that has been practiced for Andigena-based germ plasm enhancement has been to select within Andigena for adaptation to temperate conditions then to hybridize these selections with Tuberosum. This technique which is called pre-selection in this paper reduces the number of original accessions during selection resulting in loss of diversity of the enhanced germ plasm. This technique was compared to an alternative one called early hybridization, which consisted of hybridizing the Andigena introductions with Tuberosum, then practicing the same type of selection for adaptation on the hybrid population. Both techniques improved the yielding ability of the base population in subsequent selections. Even though the early hybridization technique maintained the higher mean yield in every cycle of selection, the rate of improvement was greater in the pre-selection technique. The early hybridization technique did not appear to favor the recovery of the Tuberosum genome in subsequent selections, and preserved a higher proportion of the original accessions. The most advanced population, the hybrid formed at the end of the pre-selection technique, produced greater yield and larger tuber size than the most advanced hybrid population formed in the early hybridization technique.  相似文献   

17.
Breeding studies in potatoes containing high concentrations of anthocyanins   总被引：1，自引：0，他引：1  
Studies of the breeding behavior of clones containing high levels of anthocyanins were conducted. Red-fleshed clones appeared in proportions suggesting multigenic control of degree of pigmentation. Red-fleshed and pur-ple-fleshed clones were always accompanied by red and purple skin, respectively. Red flesh ranged from partial pigmentation to complete pigmentation represented by pigment present in all tuber tissues. Percentage of com-pletely red-fleshed progeny was 14.5% and 4.1% in red x red crosses vs red × white (or the reciprocal), respectively. Purple-fleshed progeny were obtained from red x white crosses where the white-fleshed parent harbored theP pigment gene in juxtaposition with the nulliplex recessive state of theI gene (i.e.,iiii), which suppressed expression. Total anthocyanin ranged from 6.9 to 35 mg per 100 g fresh weight in the red-fleshed and 5.5 to 17.1 in the purple-fleshed clones. Red-fleshed clones contained predominantly acylated glycosides of pelargonidin while the purple-fleshed clones contained predominantly acylated glycosides of petunidin and peonidin. Oxygen Radical Absorbance Capacity and Ferrous Reducing Ability of Plasma revealed that the antioxidant levels in the red or purple-fleshed potatoes were two to three times higher than white-fleshed potato.  相似文献   

18.
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   

19.
Summary A selected clone ofSolanum tuberosum Group Andigena PI 347773 (clone Adg 11.1) and the cultivar Superior had previously been shown to be heterozygous at a gibberellin related dwarfing locus, ga1. Experiments were conducted to test for gametophytic selection for alleles at the ga1 locus in reciprocal crosses and for the effect of genotype on tuber yield. The genotypes of individuals from superior-Adg 11.1 reciprocal F1 families were determined by test crossing. Genotypic classes could be distinguished by the percentages of dwarf seedlings in their test cross progeny. No differences were found in the genotypic distributions of the reciprocal families, which indicates gametophytic selection at this locus is not the cause of reciprocal yield differences. Superior-Adg 11.1 individuals classified by ga1 locus genotype were evaluated for tuber yield. Tuber yields were highly correlated with genotype in both reciprocal families. Yields followed the pattern of simplex>duplex>triplex, indicating that the recessive mutant ga1 allele exhibited a dose effect stimulating yield.  相似文献   

20.
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   

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