Potato germplasm enhancement with disomic tetraploid Solanum acaule. I. Efficiency of introgression

Genome ◽  
1992 ◽  
Vol 35 (1) ◽  
pp. 53-57 ◽  
Author(s):  
Kazuo Watanabe ◽  
Carlos Arbizu ◽  
P. E. Schmiediche
Keyword(s):  
Efficient Method ◽  
Wild Species ◽  
Egg Production ◽  
Chromosome Doubling ◽  
Embryo Rescue ◽  
Germplasm Collection ◽  
2N Gametes ◽  
Germplasm Enhancement ◽  
Technical Problems ◽  
Solanum Acaule

The wild potato species Solanum acaule (acl) was used as a model of a disomic tetraploid Solanum species to develop systematic methods of germplasm enhancement for disomic tetraploid species. The objective was to develop a genetically efficient method to overcome the inherent technical problems encountered in the utilization of disomic tetraploid wild species. Accessions of acl were selected from CIP's wild germplasm collection and from the collection of University of Birmingham, with emphasis on genetic attributes such as PLRV resistance and (or) PSTV resistance. Four methods were tested: (i) triploids from crosses between 4x acl × 2x potato were selected for 2n gametes production and were crossed to tetraploids or to diploids with 2n egg production; (ii) axillary buds of triploid hybrids were treated with colchicine to double chromosome numbers to generate hexaploids; (iii) in vitro chromosome doubling to obtain hexaploids from triploid hybrids; and furthermore (iv) the selected acl clones were directly crossed to tetraploid potatoes followed by a combination of second compatible pollinations with IvP 35 and subsequent embryo rescue. The combination of second compatible pollination and embryo rescue was found to be the most genetically efficient method for the utilization of the valuable genetic attributes of acl.Key words: inter-EBN crosses, ploidy manipulation, polyploid, potato breeding, wild species

Overcoming crossing barriers between nontuber-bearing and tuber-bearing Solanum species: towards potato germplasm enhancement with a broad spectrum of solanaceous genetic resources

Genome ◽  
1995 ◽  
Vol 38 (1) ◽  
pp. 27-35 ◽  
Author(s):  
K. N. Watanabe ◽  
M. Orrillo ◽  
S. Vega ◽  
J. P. T. Valkonen ◽  
E. Pehu ◽  
...  
Keyword(s):  
Wild Species ◽  
Embryo Rescue ◽  
Leaf Roll ◽  
Reproductive Traits ◽  
Solanum Species ◽  
Interspecific Crosses ◽  
Potato Leaf ◽  
Germplasm Enhancement ◽  
Breeding Lines ◽  
Potato Germplasm

The first direct sexual hybrids between diploid nontuber-bearing species and diploid potato breeding lines are reported here. Three nontuberous species of Solanum, S. brevidens, S. etuberosum, and S. fernandezianum, were used for sexual crosses, achieved by a combination of rescue pollinations and embryo rescue. Initial hybrid selection was made using an embryo spot marker, followed by the evaluation of morphological and reproductive traits. Putative hybrids were first tested for resistance to potato leaf roll virus derived from the wild species, and then were tested with molecular markers using species-specific DNA probes. Finally, the tuberization of several 2x hybrids was tested for actual potato germplasm enhancement. These hybrids are unique in terms of their potential to enhance recombination between chromosomes of wild species and those of cultivated potatoes in germplasm utilization, and to exploit the genetic nature of tuber formation. The finding that nontuber-bearing Solanum spp. can be directly crossed with tuber-bearing species also has important implications for the regulatory aspects of the use of genetically modified organisms.Key words: nontuber-bearing Solanum, potato germplasm enhancement, interspecific crosses, chromosome manipulation, inter-EBN crosses, diploid.

Using disomic 4x(2EBN) potato species' germplasm via bridge species Solanum commersonii

Genome ◽  
1994 ◽  
Vol 37 (5) ◽  
pp. 866-870 ◽  
Author(s):  
J. B. Bamberg ◽  
R. E. Hanneman Jr. ◽  
J. P. Palta ◽  
J. F. Harbage
Keyword(s):  
Solanum Tuberosum ◽  
Inbreeding Depression ◽  
Chromosome Pairing ◽  
Chromosome Doubling ◽  
Embryo Rescue ◽  
Diploid Species ◽  
2N Gametes ◽  
Solanum Commersonii ◽  
Potato Germplasm ◽  
Bridge Species

The cultivated potato Solanum tuberosum Dunal has many wild related species with desirable traits. Some of these wild tetraploids have disomic chromosome pairing, ready selfing with little inbreeding depression, but have strong crossing barriers with cultivars. They hybridize most easily with 2EBN forms (which include most diploid species). Chromosome doubling to the 8x level, use of 2n gametes, use of 2n gametes of 4x–2x triploid hybrids, and embryo rescue have been proposed to overcome the crossability barrier of these species with S. tuberosum. In this study, 2x S. commersonii (cmm) was used as a bridge species with S. acaule and series Longipedicellata species. Synthetic tetraploid 4x-cmm crossed readily to disomic 4x species, resulting in fertile F1 and F2 hybrids. Some of these had 2n gametes, which enabled direct crossing to tuberosum, resulting in 6x hybrids. The benefits of this scheme are (i) hybrids are relatively fertile, so many progeny may be produced for selection at each step, (ii) hybridization with cmm results in 2n gametes needed for crossing to tuberosum, and breaks up restricted recombination within disomic genomes, and (iii) simple techniques and tools are employed.Key words: Solanum, potato, germplasm, crossability.

scholarly journals Interploid Hybridization of Cucumis melo and C. metuliferus

1999 ◽  
Author(s):  
Jeff Adelberg ◽  
Halina Skorupska ◽  
Bill Rhodes ◽  
Yigal Cohen ◽  
Rafael Perl-Treves
Keyword(s):  
Wild Species ◽  
Chromosome Doubling ◽  
Fertility Restoration ◽  
Embryo Rescue ◽  
Early Spring ◽  
Late Winter ◽  
Crop Species ◽  
Primary Focus ◽  
First Time

The long-term motivation for this research is to transfer useful traits from a broad based gene pool of wild species into the narrow base of a cultivated crop in Cucumis. Our primary focus was to use polyploid prior to fertilization as a tool to overcome fertility barriers in the cross between C. melo and C. metuliferus. In conducting this research, we explored all combinations of tetraploid and diploid parents, in reciprocal combinations. Pollinations were made in both the field and greenhouse, using emasculated flowers, moneocious females, and open pollination by insect vectors, with morphological selection criteria. After observations of thousands of ovaries, we still have no definitive proof that this hybridization yielded viable embryos. The most promising results came from using tetraploid C. metuliferus, as the maternal parent in the interspecific hybridization, that set fruit were seeds contained small embryos that did not germinate. To obtain fruit set, it was important to rear plants in a cooler sunny greenhouse, as would be found in late winter/early spring. A second interspecific hybrid between wild and cultivated Cucumis, C. hystrix x C. sativus, yielded fertile progeny for the first time, while concomitantly working toward our primary goal. Two distinct treatments were necessary; 1) special plant husbandry was necessary to have the wild species produce fruit in cultivation, and 2) embryo rescue followed by chromosome doubling in vitro was required for fertility restoration. Backcrosses to crop species and resistance to nematodes are compelling areas for further work.

scholarly journals ValSten: a new wild species derived allotetraploid for increasing genetic diversity of the peanut crop (Arachis hypogaea L.)

2021 ◽  
Author(s):  
Dongying Gao ◽  
Ana C. G. Araujo ◽  
Eliza F. M. B. Nascimento ◽  
M. Carolina Chavarro ◽  
Han Xia ◽  
...  
Keyword(s):  
High Resistance ◽  
Wild Species ◽  
Chromosome Doubling ◽  
Crop Improvement ◽  
Snp Array ◽  
Great Majority ◽  
Morphological Variations ◽  
Peanut Crop ◽  
Cultivated Peanut ◽  
Wild Peanut

AbstractIntrogression of desirable traits from wild relatives plays an important role in crop improvement, as wild species have important characters such as high resistance to pests and pathogens. However, use of wild peanut relatives is challenging because almost all wild species are diploid and sexually incompatible with cultivated peanut, which is tetraploid (AABB genome type; 2n = 4x = 40). To overcome the ploidy barrier, we used 2 wild species to make a tetraploid with the same allotetraploid genome composition as cultivated peanut. Crosses were made between 2 diploid wild species, Arachis valida Krapov. and W.C. Greg. (BB genome; 2n = 2x = 20) and Arachis stenosperma Krapov. and W.C. Greg. (AA genome; 2n = 2x = 20). Cuttings from the diploid F1 AB hybrid were treated with colchicine to induce chromosome doubling thus generating an induced allotetraploid. Chromosome counts confirmed polyploidy (AABB genome; 2n = 4x = 40). We named the new allotetraploid ValSten. Plants had well-developed fertile pollen, produced abundant seed and were sexually compatible with cultivated peanut. ValSten exhibits the same high resistance to early and late leaf spot and rust as its diploid parents. Notably, we observed morphological variations, including flower width and branch angles in the earliest generation (S0) of allotetraploids. A SNP array was used to genotype 47 S0 allotetraploids. The great majority of markers showed the additive allelic state from both parents (AABB). However, some loci were AAAA or BBBB, indicating homeologous recombination. ValSten provides a new, vigorous, highly fertile, disease resistant germplasm for peanut research and improvement.

Genome affinity and meiotic behaviour in trigenomic hybrids and their doubled allohexaploids between three cultivated Brassica allotetraploids and Brassica fruticulosa

Genome ◽  
2012 ◽  
Vol 55 (2) ◽  
pp. 164-171 ◽  
Author(s):  
J.P. Chen ◽  
X.H. Ge ◽  
X.C. Yao ◽  
Z.Y. Li
Keyword(s):  
Wild Species ◽  
Chromosome Doubling ◽  
Brassica Species ◽  
Low Fertility ◽  
Meiotic Behavior ◽  
Homologous Pairing ◽  
Mother Cells ◽  
Relationship Of ◽  
Brassica Fruticulosa ◽  
Cytological Behaviour

The wild species Brassica fruticulosa Cyr. (FF, 2n = 16) is closely related to the cultivated Brassica species. Through interspecific reciprocal crosses between B. fruticulosa and three cultivated Brassica allotetraploids (AABB, AACC, and BBCC where A = 10, B = 8, and C = 9), four trigenomic hybrids (F.AC, 2n = 27; F.AB, 2n = 26; F.BC, 2n = 25; BC.F, 2n = 25) were produced. By chromosome doubling of respective hybrids, three allohexaploids (FF.AACC, 2n = 54; FF.AABB, 2n = 52; BBCC.FF, 2n = 50) were synthesized. In pollen mother cells (PMCs) of the trigenomic hybrids, 1–2 autosyndetic bivalents were detected within A, B, and C genomes but only one within F genome; 1–3 allosyndetic bivalents between any two genomes were observed, and a closer relationship of F and B genomes than F and A genomes or F and C genomes was revealed. The allohexaploids showed a generally low but different pollen fertilities. The chromosomes in PMCs were predominantly paired as bivalents but some univalents and multivalents at variable frequencies were observed. The bivalents of homologous pairing for each genome prevailed, but allosyndetic quadrivalents and hexavalents involving any two genomes were observed, together with autosyndetic quadrivalents for A, B, and C genomes but not the F genome. The nondiploidized cytological behaviour of these allohexaploids contributed to their low fertility. The relationships between the genome affinity and meiotic behavior in these allohexaploids were discussed.

Use of Ipomoea trifida (HBK.) G. Don germ plasm for sweet-potato improvement. 2. Fertility of synthetic hexaploids and triploids with 2n gametes of I. trifida, and their interspecific crossability with sweet potato

Genome ◽  
1991 ◽  
Vol 34 (2) ◽  
pp. 209-214 ◽  
Author(s):  
Rosanna Freyre ◽  
Masaru Iwanaga ◽  
Gisella Orjeda
Keyword(s):  
Sweet Potato ◽  
Egg Production ◽  
Ipomoea Batatas ◽  
2N Gametes ◽  
Pollen Production ◽  
2N Pollen ◽  
Ipomoea Trifida ◽  
Potato Improvement ◽  
Synthetic Hexaploids ◽  
Interspecific Crossability

Twenty-two synthetic hexaploids and 33 triploids with 2n pollen production of Ipomoea trifida were used in crosses to estimate their male and female fertility and their crossability with sweet potato, Ipomoea batatas (L.) Lam. Several important conclusions were drawn. (i) The fertility of pollen of the triploid plants was confirmed, which suggested they are truly functional 2n pollen. (ii) The average male fertility of hexaploid plants was higher than that of triploid with 2n pollen production plants. (iii) 2n egg production was observed in several triploid genotypes, (iv) From a polycross, 3079 seeds with normal shapes were produced. These represent a population of hexaploid I. trifida with a wide genetic base, and they may be important material for sweet-potato improvement, (v) A total of 3275 seeds were obtained from crosses with six sweet-potato female parents, of which only 60 germinated, indicating the existence of an interspecific barrier. The implications of 2n gametes for breeding and evolution of sweet potato are also discussed.Key words: Ipomoea batatas, Ipomoea trifida, 2n gametes, sexual polyploidization, triploid.

An efficient method for immature embryo rescue and plant regeneration from the Calli ofZiziphus jujuba‘Lengbaiyu’

2018 ◽  
Vol 94 (1) ◽  
pp. 63-69 ◽  
Author(s):  
Haiyan Ren ◽  
Xuemei Du ◽  
Dengke Li ◽  
Ailing Zhao ◽  
Yongkang Wang ◽  
...  
Keyword(s):  
Plant Regeneration ◽  
Efficient Method ◽  
Embryo Rescue ◽  
Immature Embryo

scholarly journals Estimation of Fruit Grade Weights Based on Fruit Number and Total Fruit Weight in Cucumber

HortScience ◽  
2002 ◽  
Vol 37 (7) ◽  
pp. 1117-1121 ◽  
Author(s):  
Nischit V. Shetty ◽  
Todd C. Wehner
Keyword(s):  
Efficient Method ◽  
Germplasm Collection ◽  
Plant Introduction ◽  
Fruit Weight ◽  
Fruit Number ◽  
Cucumber Fruit ◽  
The U.S

In many cases, measurement of cucumber fruit weight in small research plots involves more labor and resources than just counting the number of fruit per plot. Therefore, plant breeders are interested in an efficient method for estimating fruit weight per grade (early, marketable, and cull) based on fruit number and total fruit weight. We evaluated the cucumber germplasm collection of 810 plant introduction accessions (supplied by the U.S. Dept. of Agriculture, Regional Plant Introduction Station at Ames, Iowa) along with seven check cultivars for yield. Correlations were calculated for all pairs of fruit number and fruit weight combinations for each grade. In general, the lowest correlations were observed between the fruit weight of each grade (early, marketable, and cull) and total fruit weight or number per plot. High correlations were observed for fruit weight and fruit number within each grade (early, marketable, and cull). An efficient method for estimating fruit weight per hectare of early, marketable, and cull grades is to count total, early, and cull fruit, then measure total fruit weight. Our results showed that the fruit weight of each grade (early, marketable, and cull) was best estimated using the fruit number of that grade (early, marketable, and cull) along with the total fruit weight and total fruit number.

Occurrence and mechanisms of 2n egg formation in 2x potato

Genome ◽  
1991 ◽  
Vol 34 (6) ◽  
pp. 975-982 ◽  
Author(s):  
Joanna E. Werner ◽  
Stanley J. Peloquin
Keyword(s):  
Wild Species ◽  
Seed Set ◽  
2N Gametes ◽  
Origin And Evolution ◽  
First Division Restitution ◽  
Egg Formation ◽  
Second Division Restitution ◽  
2N Eggs ◽  
Haploid Species ◽  
Species Hybrids

The occurrence of 2n eggs in 381 haploids from six tetraploid parents and in 127 plants representing five diploid wild species was detected using 2x × 4x crosses. Sixty-two percent of the haploids and 24% of the wild-species plants produced 2n eggs. Twenty-six haploids and 17 species plants that gave high seed set in 2x × 4x crosses were examined cytologically to determine the frequency and mechanisms of 2n egg formation. There was significant variation in the frequency of 2n eggs among haploids (7–57%) and among species plants (4.9–57.3%). Five mechanisms of 2n egg formation were identified: synaptic variant (genetically first division restitution); delayed meiotic division (first division restitution and second division restitution); omission of the second division (the prevalent mechanism, second division restitution); irregular anaphase II (second division restitution); and failure of second cytokinesis (second division restitution). 2n eggs can be formed by more than one mechanism within a clone. The occurrence of 2n eggs in wild species and the higher frequency of 2n eggs in haploids than in wild species indicate that sexual polyploidization has been involved in the origin and evolution of polyploid series in potato. The high frequency of 2n eggs in both haploids and diploid wild species allows generation of haploid-species hybrids that produce 2n eggs. These hybrids can then be used in the 2x × 4x and 2x × 2x breeding schemes.Key words: haploids, wild species, 2n gametes, first division restitution, second division restitution.

scholarly journals Multi-crops Germplasm Collection from Far Western Development Region of Nepal

2013 ◽  
Vol 14 ◽  
pp. 55-64 ◽  
Author(s):  
Salik R Gupta ◽  
Hari B KC ◽  
Uma S Shah ◽  
Dayanand Mandal ◽  
Mukund Bhattarai
Keyword(s):  
Genetic Resources ◽  
Wild Species ◽  
Random Sampling ◽  
Sampling Method ◽  
Germplasm Collection ◽  
Agricultural Crops ◽  
Genetic Base ◽  
Western Development ◽  
Development Region ◽  
Unexplored Area

To widen the genetic base for further improvement, it is necessary to collect, characterize, evaluate and conserve multi-crops genetic resources. Collection of germplasm from unexplored area was conducted during 2011. A total of 504 samples were collected from Far-Western Development Region of Nepal including a wild species of rice Oryza ruffipogon Griff from Ghoda ghodi tal of Kailali district. A random sampling method was followed for most agricultural crops, where populations were large, and variability was deliberately sought. Sampling was from household stores and from harvested lots, together with individual sampling from fields and markets where appropriate. Greater diversity was found in rice (116) followed by soybean (38), maize (35), beans (28), cowpea (26) and wheat (24). The major achievements of these collections were recognized as the acquisition of additional variability for different multi-crop genetic resources.

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