共查询到20条相似文献，搜索用时 31 毫秒
1.
Satish Kumar Luthra Jagesh Kumar Tiwari Mehi Lal Poonam Chandel Vinod Kumar 《Potato Research》2016,59(4):375-391
Ten tetraploid interspecific potato somatic hybrids developed earlier through protoplast fusion between the dihaploid Solanum tuberosum L. ‘C-13’ and the diploid wild species Solanum pinnatisectum Dun. were used in this study. Somatic hybrids and standard control cultivars were evaluated for adaptability, tuber traits, late blight resistance and keeping quality attributes (dormancy, sprouting, weight loss and appearance after 75 days of storage) during two successive winter crop seasons (short-days) in the sub-tropical plains of India, where nearly 90% of India’s potatoes are grown. Somatic hybrids showed medium to good plant vigour and late to very late plant maturity. Though none of the somatic hybrids produced equal or higher tuber yield than the control cultivars, except clone P7, all other somatic hybrids produced significantly higher marketable and total tuber yield after a 90-day growth than the parent C-13. Most of the somatic hybrids possessed higher tuber dry matter concentration, resistance to late blight and better keeping quality attributes than the control cultivars. Notably, the tubers of somatic hybrids showed a tendency for colour change from white to purple on exposure to sunlight. Breeding potential of somatic hybrids was further assessed by crossing them with commonly grown local potato cultivars for the development of backcross (BC1) progenies. In the hybridization programme, berries were formed while somatic hybrids were used either as male or female parents with common cultivars. Our results revealed that the use of bulk pollen of somatic hybrids not only resulted in higher pollination success but also helped to achieve higher numbers of true potato seeds (TPS) per berry. Despite the formation of berries, TPS was absent in 22 crosses using somatic hybrids as a female or male parent which may be due to ovule or embryo abortions. Segregating BC1 generations were evaluated under the same sub-tropical conditions for further exploitation in potato breeding. Based on our study, the somatic hybrids P4, P8 and P10 can be utilized for the introgression of important characters such as high tuber dry matter concontration, resistance to late blight and excellent keeping quality attributes into the cultivated potato via conventional breeding methods for cultivar development in the sub-tropical plains of India. 相似文献
2.
Suhas R. Ghate Casimir A. Jaworski Sharad C. Phatak 《American Journal of Potato Research》1983,60(7):557-562
Pregermination of true potato seeds obtained from open pollination of breeding lines and F1, hybrids improved the emergence and stand in a warm climate. Considerable differences in emergence existed within the breeding lines and F1 hybrids. With proper selection of breeding lines and pregermination of seeds, it would be possible to obtain a desirable plant stand in a warm climate. 相似文献
3.
Summary Functional female fertility (FFF) and functional male fertility (FMF) were studied in diploid potato clones, includingS. tuberosum haploids, F1 hybrids between haploids and otherSolanum species, and in progenies from subsequent hybridisations. The results of 402 crosses between 91 diploid potato clones revealed
that 60% of all genotypes had low levels of FFF as well as low levels of FMF regardless of their origin and degree of hybridity.
Failed crosses (without any fruits at all) and those with a low level of success (with less than 3 seeds per pollinated flower)
constituted 69% of all studied crosses. Most of these had resulted from parents with low levels of FFF and FMF, and these
two characteristics were expressed independently. Functional female fertility affected crossability behaviour no less than
FMF, therefore both FFF and FMF should be controlled in diploid potato clones involved in breeding. Reliable FFF and FMF estimates
can be based only on crossing results. The coefficient of multiple correlation between seeds per pollinated flower in crosses
and FFF and FMF estimates of the parental clones was 0.80 (P<0.01). Hence the compilation and analysis of the results of diploid
potato crosses allow a reliable assessment of FFF and FMF and consequently the prediction of crossability with a degree of
sufficient accuracy. 相似文献
4.
Diploid (2n = 2× = 24) potato (Solarium) species that produce 2n gametes are being utilized in potato breeding programs. Three breeding schemes involving these diploids are presently used by potato breeders to transfer this genetic material from diploid parents to their tetraploid offspring. Derived tetraploids may arise through tetraploid × diploid, tetraploid × haploid-species, or diploid × diploid hybridizations. The inbreeding coefficient of derived tetraploids is a complex function of the coancestry of the parents, the inbreeding of the parents, the coefficient of double reduction in the tetraploid parent, and the frequency of single exchange tetrads in the diploid parent(s), and it depends on the mechanism of 2n gamete formation. For the two breeding strategies involving tetraploid female parents, there is less inbreeding in the derived tetraploid from a diploid parent producing 2n pollen by first division restitution than 2n pollen by second division restitution when the frequency of single exchange tetrads in the diploid is less than 2/3. In bilateral sexual polyploidization, the inbreeding coefficient of a derived tetraploid for a given set of parents from a first division × first division restitution cross is less than the inbreeding coefficient of a second division × first division restitution cross which is less than the inbreeding coefficient of a second division × second division cross when the frequency of single exchange tetrads is less than 2/3. 相似文献
5.
Selecting an effective tester for evaluating the hybrid performance and heterosis of new inbred lines is crucial to ensure their accurate evaluation. Most sorghum breeding programs use at least two elite inbred line testers when evaluating new inbred lines. These testcrosses provide valuable information, but the specificity of inbred line testers may incorrectly characterize experimental lines that would combine well with other genetic backgrounds. Reducing this risk by increasing the number of preliminary testcrosses is limited in breeding programs by resource availability. Efficiently diversifying testcrosses may be accomplished through the use of F1 testers. Testcrosses made with F1 testers simultaneously evaluate inbred lines against two genetic backgrounds. In preliminary testcrosses, this may reduce the probability of incorrectly discarding new lines or improve the efficiency of preliminary testcrossing. The objective of this research was to compare two sorghum inbred line testers to their respective F1 as a tester for evaluating sorghum inbred lines (R-lines) in testcrosses for grain yield. The testers used were A.Tx623, A.Tx2752 and their F1 hybrid, A.Tx623/B.Tx2752. Data from testcross hybrids from 33 different inbred lines grown in three environments indicated that the F1 tester was comparable in accuracy and discriminatory efficiency to the inbred line testers. The results indicated that a single cross tester in sorghum can serve to effectively evaluate new germplasm. 相似文献
6.
以不同类群骨干自交系PH4CV、Mo17、PH6WC、郑58、D299、H29、丹黄34、丹598、昌7-2和S121为基础试材,按照群内和群间杂交共组配15个基础群体,分别形成F1、F2、F3和F4共4个自交世代,研究其单倍体诱导率和加倍率。利用高频诱导系丹诱3号对骨干自交系和不同遗传基础的自交后代进行单倍体诱导,利用浓度为0.06%的秋水仙素对各世代单倍体子粒进行加倍处理。结果表明,不同种质类群自交系间诱导率存在显著差异,以Lancaster群代表系PH4CV、Mo17和Reid群代表系PH6WC、郑58诱导率较高。高诱导率类群通过群内和群间组配基础试材,同样具有较高的诱导率,同时利用杂种优势提升了LRC、SPT和PB群骨干系的诱导率。诱导率随着自交世代增加而显著降低,在F2世代加倍效果最好。 相似文献
7.
《Field Crops Research》1998,55(3):275-281
A systematic and objective breeding strategy is proposed, involving three stages of selection carried out at the F1, F3 and F6 generations of pedigrees founded on single crosses between inbred parents. The first two of these stages involve selection between pedigrees and the third, selection within the pedigrees that survive the first two stages of scrutiny. The key features of this procedure are: that selection within pedigrees is delayed until individuals are effectively homozygous; that all characters are measured directly; and that decisions are based on the performance of plants that are raised in replicated and randomised trials. The replacement of the pedigree method by the new method should allow breeders to recognise and exploit the genetical variation between and within their crosses for characters of interest more efficiently than hitherto at an appreciably lower cost. While this new method has been proposed in response to a specific problem with rice, it is applicable to all crop plant species where the end products of breeding programmes are inbred lines. 相似文献
8.
9.
Clones selected from the wild diploid species,Solanum berthaultii, have been shown to possess valuable levels of resistance to the Colorado potato beetle (Leptinotarsa decemlineata), as well as to insects such as aphids, flea beetles, leafhoppers and the potato tuber moth. Resistance is associated with the presence of glandular trichomes on the foliage ofS. berthaultii (2). Six generations after producing a hybrid between the diploid species and a tetraploid variety, a clone with good beetle and leafhopper resistance, as well as reasonable agronomic characteristics has been produced. 相似文献
10.
Summary Successive generations of open pollinated (OP) true potato seed (TPS) families represent a low-cost planting material. This
study was conducted to determine whether inbreeding occurred during two successive OP generations and, if so, whether it adversely
affected the performance of transplant families from true seed. Potato seedling transplants from 4x×2x hybrid, OP1, OP2, S1 and S2 families were compared for plant vigour, flowering, pollen stainability, OP fruit set, tuber yield and specific gravity.
Hybrids were consistently superior, while S2 families were inferior. The performance of OP1, OP2 and S1 families did not differ significantly for most traits. The accumulation of inbreeding in successive OP generations was limited
by reduced OP seed production on selfed plants; thus, a synthetic TPS variety propagated by open pollination may be feasible.
Paper no. 3162 from the Department of Genetics, University of Madison. 相似文献
11.
E. E. Ewing I. Simko E. A. Omer P. J. Davies 《American Journal of Potato Research》2004,81(4):281-289
Efforts to breed for the ability to tuberize under long days or for the length of tuber dormancy should benefit not only from information on the location of genes associated with these traits, but also from an understanding of the hormones the genes control. Understanding the role of the respective genes is a logical step in developing the best breeding strategy, both for conventional breeding and for gene transfer using molecular techniques. Polygene mapping affords a way to achieve such understanding and is also a tool to study the physiology of potato tuberization and potato tuber dormancy. The addition of DNA markers to a plant population facilitates the mapping of polygenes that control quantitatively inherited traits segregating in the population. A quantitative trait locus denotes a region of chromosome that is linked to the marker gene and which has a significant effect on the quantitative trait under study. Our approach has been to find the quantitative trait loci associated with tuberization and tuber dormancy in a segregating diploid population, and then to map the population for quantitative trait loci associated with levels of hormones implicated in the control of these two traits. We are using a population derived from a hybrid between haploidSolanum tuberosum andS. berthaultii that was backcrossed to a different haploidS. tuberosum. We have found ten quantitative trait loci for the ability to tuberize under long days and eight quantitative trait loci for tuber dormancy. In the same population we have found one or more quantitative trait loci for polyamines, abscisic acid, tuberonic acid, tuberonic acid glucoside, zeatin riboside, and gibberellin A1. Some of the hormone quantitative trait loci have coincided with quantitative trait loci for tuberization or dormancy. Implications of such commonality are discussed, along with the usefulness and limitations of the methods. 相似文献
12.
马铃薯4x×2x杂种无性一代产量及产量性状的表现 总被引：1，自引：0，他引：1
产生２ｎ花粉的Ｎｅｏ－ｔｕｂｅｒｏｓｕｍ双单倍体×Ｓｏｌａｎｕｍｐｈｕｒｅｊａ的二倍体杂种以及其与Ｎｅｏ－ｔｕｂｅｒｏｓｕｍ双单倍体的回交后代与普通马铃薯（Ｓ．ｔｕｂｅｒｏｓｕｍｓｓｐ．ｔｕｂｅｒｏ ｓｕｍ品种东农３０３进行了杂交。４ｘ杂种在株高方面表现出了很强的杂种优势。商品薯产量与４ｘ亲本无显著差异，但两个杂种群体的最高值分别超４ｘ亲本的２６０ｇ／株和６０ｇ／株。总产量杂种优势明显，但杂种单株结薯数多，平均块茎重小，这些是限制４ｘ×２ｘ杂种利用的不利因素，需要进一步地改善。 相似文献
13.
Soft rot of potato tubers, caused byErwinia (Pectobacterium), is a serious disease affecting potato crops during storage. Studies on the inheritance of resistance to tuber soft rot were undertaken on diploid potato hybrids. A total of 480 clones, derived from 12 families, were examined for resistance to soft rot in laboratory tests over 3 years and for basic agronomic traits in field experiments over 2 years. General (GCA) and specific (SCA) combining abilities were significant in the inheritance of resistance to soft rot; however, GCA for female parents were significant in 1 or 2 years during 3 years of evaluation and SCA was significant for eight, two, and six families out of 10 tested in 1994, 1995, and 1996, respectively. There were also significant differences between years. Moreover, marked interactions for GCAfemales × year and SCA × year in the variation of soft rot resistance were found. Broad-sense and narrowsense heritability of resistance, measured as diameter of rotten tissue, was estimated as 0.92 and 0.89, respectively. The maternal effect, evaluated in two sets of reciprocal crosses, was not significant for the genetic determination of resistance to soft rot. No significant relationships were found between resistance to soft rot and the main agronomic traits in the tested diploid families. These results suggest that diploid potato clones with resistance to soft rot can be selected after being evaluated over a few seasons. It is also possible to select clones combining good resistance to soft rot with high yield, superior tuber characteristics, and acceptable starch content. These resistant diploids can be used as male parents in 4x-2x crosses in breeding tetraploid potato resistant to soft rot. 相似文献
14.
Breaking primary dormancy in seeds of the perennial pasture legume tedera (Bituminaria bituminosa C.H. Stirt. vars albomarginata and crassiuscula) 
下载免费PDF全文
下载免费PDF全文 M. Castello J. S. Croser M. M. Lulsdorf P. Ramankutty A. Pradhan M. N. Nelson D. Real 《Grass and Forage Science》2015,70(2):365-373
Tedera (Bituminaria bituminosa vars. albomarginata and crassiuscula) is a perennial pasture species with agronomic characters ideally suited to Mediterranean climates. Tedera seed has a period of after-ripening or primary dormancy typically lasting three months, which delays assessment and breeding of elite hybrid varieties. Temperature, chemical and mechanical methods were investigated in conjunction with in vitro culture to circumvent this dormancy period across a range of parental and hybrid genotypes. Temperature treatment of T5 (Tedera accession 5) and T48 (Tedera accession 48) alone was not sufficient to break dormancy (24.0% and 14.7% germination); however, when combined with soaking in gibberellic acid (GA3) and mechanical scarification resulted in 79.7% and 84.3% germination respectively. In an effort to further improve this result for valuable hybrid genotypes, we combined mechanical scarification with removal of seed coat after imbibition and in vitro culture on B5 medium until radicle emergence. This resulted in breaking dormancy from 96% to 100% of parent seeds and 100% of hybrid seeds. Hardening the germinated F1 or F2 seedlings 4 d after first transfer to in vitro culture resulted in 100% survival of plants to soil. This procedure is now used on a routine basis in the Australian tedera breeding programme. 相似文献
15.
Ryan C. Graebner Charles R. Brown Russell E. Ingham Christina H. Hagerty Hassan Mojtahedi Richard A. Quick Launa L. Hamlin Nadine Wade John B. Bamberg Vidyasagar Sathuvalli 《American Journal of Potato Research》2018,95(6):679-686
Meloidogyne chitwoodi (Columbia root-knot nematode, CRKN) can cause serious damage in potato production systems, decreasing tuber value in the fresh market and processing industries. Genetic resistance to CRKN was first identified from the wild diploid potato species Solanum bulbocastanum accession SB22 and was successfully introgressed into tetraploid potato breeding material. To expand the base of genetic resistance, 40 plant accessions representing nine wild potato species were screened for their resistance to M. chitwoodi. Greenhouse screening identified fifteen clones from S. hougasii, one clone from S. bulbocastanum, and one clone from S. stenophyllidium with moderate to high levels of resistance against three isolates of M. chitwoodi. Geographical mapping showed that the resistance sources identified in this and previous studies primarily originated in the states of Jalisco and Michoacán in west-central Mexico. These new sources of resistance will be introgressed into elite potato populations to facilitate the development of potato cultivars with durable resistance to M. chitwoodi. 相似文献
16.
Recently proposals have been made in both Europe and North America to try to radically change potato breeding strategy from a tetraploid, heterozygous crop to a diploid inbred crop. As part of that effort, clones from the long-day adapted, late blight resistant diploid hybrid Solanum phureja – S. stenotomum population were selfed to begin the process of developing inbred lines. In March of 2016 and 2017, 42 diploid clones from the above-mentioned population were selfed in the greenhouse in Beltsville, MD. In 2016 and 2017, 10 and 13 clones failed to flower, respectively. Among the remaining clones, 716 pollinations were made in 2016, resulting in 57 fruit from 17 clones, and 3742 seeds; 801 pollinations were made in 2017, resulting in 34 fruit from 12 clones, and 1903 seeds. Nine clones were successfully selfed both years. Percent successful selfs was significantly higher in 2016 (7.96%) than in 2017 (4.24%). The most prolific clones in 2016 were BD1241–1 (34% successful selfs, 1090 seed), BD1218–3 (25% successful selfs, 638 seed), BD1215–1 (5% successful selfs, 411 seed), BD1243–1 (23% successful selfs, 232 seed). In contrast, the most prolific clones in 2017 were BD1230–2 (25% successful selfs, 537 seed), BD1203–3 (23% successful selfs, 391 seed), and BD1229–1 (11% successful selfs, 388 seed). These results indicate that there is sufficient self-compatibililty in this population to generate large numbers of inbred individuals, but that genotype x environment interactions are large. Attempts to generate selfed seed should be made over several years to maximize the genetic base of the selfed population. 相似文献
17.
18.
Theodora Karanisa Alexios A. Alexopoulos Georgios Tsaniklidis Ioannis C. Karapanos Konstantinos A. Akoumianakis 《Potato Research》2016,59(4):345-356
Chemical agents may be used to overcome dormancy in potato tubers so as to permit early planting. In this paper, the effect of carbon disulphide on sprouting and related metabolic processes in potato tubers grown from true potato seed (TPS) was investigated. Carbon disulphide was applied to potato tubers derived from TPS, at a rate of 20 ml m?3 container volume for 72 h. It accelerated tuber sprouting and increased tuber weight loss. It also caused an increase in the respiration rate, as well as ethylene emission from the tubers during the first 6 days after treatment. The respiration rate of carbon disulphide-treated tubers remained at a higher level than that of untreated controls for 35 days after treatment. In addition, carbon disulphide increased the concentrations of the soluble sugars sucrose and fructose, but not glucose, in the tuber tissues (buds, parenchyma). These findings suggest that carbon disulphide releases potato minitubers from dormancy and that dormancy breakage is associated with changes in tuber metabolism prior to the visible sprouting. 相似文献
19.
Introductions of 13 frost-resistant diploid (2n=2x=24)Solanum species (2 non-tuberous) were inter-crossed to produce F1 hybrids involving two frost resistance sources. Successful F1 combinations were: (i) inter-crossed to produce hybrids involving 3 to 4 frost resistance sources, (F1×F1); and (ii) crossed with haploids (2n=24) of frost-susceptible tetraploid (2n=4x=48)S. tuberosum subsp.tuberosum, (F1×tbr). Thirty-five of the 75 crosses between the 13 species produced viable seed. The F1 and F1×F1 progenies segregated to yield plants more resistant to freezing temperatures than the parental species. All attempts to cross these hybrids with 24-chromosometbr were successful. Although tuber production improved following the first cross totbr, the frequency of resistant plants decreased approximately 50%. Thus far, all first back-cross attempts, (F1×tbr)×tbr, have succeeded. Utilizing hybrids synthesized from several sources of frost resistance as the donor parents, and clonal selections of 24-chromosometbr as the recurring parents, may provide a high order of resistance throughout the backcrossing program and implement selection of frost-resistant, long-day tuberizing parental stocks acceptable to the potato breeder. 相似文献
20.
M. J. De Maine 《Potato Research》1994,37(2):173-181
Summary Comparisons were made between tetraploid progenies obtained by crossing dihaploid and chromosome doubled dihaploid potatoes
with tetraploids. Dihaploids obtained from a doubled dihaploid produced some progenies from 2xx4x crosses which were as high
yielding and had as good tuber characteristics as control progenies produced by intercrossing heterozygous tetraploids. It
was found that there was a slight reduction in tuber yield associated with inbreeding but selection could be made among highly
inbred material for useful parents.
Other characters were little affected by inbreeding. It was concluded that haploidisation and chromosome doubling could be
used to produce homozygous clones for use by breeders without greatly depressing the agronomic value of their offspring. 相似文献