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1.
H. T. Stalker 《Euphytica》1984,33(2):529-538
Summary Advanced generation 40-chromosome hybrids between A. hypogaea (2n=4x=40) and a wild diploid species. A. cardenasii were evaluated for early leafspot, Cercospora arachidicola resistance and agronomic potential. The objective of this investigation was to determine if early leafspot resistance derived from a wild species could be incorporated into the A. hypogaea genome. Interspecific hybrid selections were made and then compared in the field and greenhouse to susceptible cultivars and to A. hypogaea lines which are reported to be resistant to early leafspot. Significantly higher levels of resistance were found in five hybrid selections than in cultivated lines based on numbers of lesions per leaf. In a greenhouse study, several hybrid selections also had greatly reduced sporulation from lesions as compared to A. hypogaea. Several mechanisms of resistance are believed to be present. Although hybrid selections had small seeds and low yields as compared to A. hypogaea, a new and valuable source of early leafspot resistance derived from the species A. cardenasii is present.Paper no. 8814 of the journal series of the North Carolina Agricultural Research Service, Raleigh, NC 27695. This research was partially funded by AID-Peanut CRSP grant DAN-4048-G-SS-2065-00. 相似文献
2.
Summary Introgression of germplasm from diploid wild Arachis species to A. hypogaea has great potential for improving pest resistance in cultivated peanuts. This investigation evaluated methods for incorporating exotic germplasm into cultivated peanuts, especially for Cercospora arachidicola
Hori resistance. Interspecific hybrids between A. hypogaea (cvs. NC 2 and NC 5) and the wild species A. cardenasii
Krap. et Greg.
nom. nud. and A. chacoense
Krap. et Greg.
nom. nud. were analyzed cytologically and for leafspot resistance. All F1 hybrids were sterile, had irregular meiosis, and very few multivalents. They were highly resistant to C. arachidicola in field tests and had a 10-fold reduction of conidia per lesion in the greenhouse as compared to A. hypogaea cultivars. After colchicine treatments of F1 hybrids, hexaploids (2n=60) and aneuploids (2n=54, 56, 63) were observed. The hexaploids had up to 18 univalents per pollen mother cell and very few multivalents, indicating a low frequency of intergenomic chromosome pairing. For C. arachidicola resistance, significant differences were not found among wild species parents, F1 hybrids and two generations of hexaploids. Most hexaploids were stable at 2n=60 and embryos aborted when backcrosses with the respective wild species were attempted. However, when hexaploids were backcrossed to A. hypogaea, several fertile pentaploid (2n=50) offspring were obtained. Use of self-pollinating pentaploids is believed to be the quickest method to recover 40-chromosome hybrid derivatives in these hybrids. 相似文献
3.
Summary Two cycles of recurrent selection for yield were previously conducted using a population of Arachis hypogaea L.-like tetraploid hybrid derivatives selected from among the progeny of a cross between A. hypogaea and A. cardenasii Krap. et Greg. nom. nud., a diploid species with resistance to late leafspot (Cercosporidium personatum (Burk. and Curt.) Deighton). Using the 10 highest yielding parents from each of the above cycles of recurrent selection, a study was conducted for 12 morphological traits and susceptibility to leafspot infection in a replicated test at a single location. The two parents used to initiate the interspecific hybrid population (PI 261942-3 and A. cardenasii) as well as two adapted cultivars (Florigiant and NC 7) were included as checks. The objectives of the study were to determine the amount of genetic variation remaining in the population after two cycles of recurrent selection in order to predict whether further progress from selection could be expected and determine the potential for utilizing wild species for the improvement of quantitative traits in peanut. The results indicate that significant levels of genetic variation remain in the population after two cycles of recurrent selection for all traits measured, including several components of yield and leafspot resistance. This suggests that continued progress in population improvement from further cycles of selection should be possible while enhancing the genetic diversity of cultivated peanut germplasm.Paper no. 12347 of the Journal Series of the North Carolina Agric. Res. Serv., Raleigh, NC 27695-7643. This work was partially funded by the Peanut CRSP, USAID grant number DAN-4048-G-SS-2065-00. Recommendations do not represent an official position or policy of USAID. 相似文献
4.
Summary Cytological studies of wild diploid Arachis species in the same section of the genus (sect. Arachis) as the cultivated peanut A. hypogaea L. show, with one exception, a karyotype characterized by the presence of 9 pairs of larger chromosomes and one pair of small (A) chromosomes. The exceptional species A. batozocoi
Krap. et Greg. has a more uniform karyotype. Interspecific hybrids between diploid species of similar karyotype have moderate to high pollen stainability, those involving A. batizocoi have zero pollen stainability and a very irregular PMC meiosis. Such infertile hybrids are the most likely to produce fertile, stable amphidiploids on doubling the chromosome complement. It is suggested that the cultivated peanut could have originated from such a sterile interspecific hybrid and on morphological and phytogeographic grounds the most likely genome donors are A. cardenasii (nomen nudum) and A. batizocoi of the species within section Arachis, which have been collected up to the present time.Paper number 5560 of the Journal Series of the North Carolina Agricultural Experiment Station, Raleigh, NC 27650 相似文献
5.
RFLP analysis of genetic variation in species of section Arachis, genus Arachis (Leguminosae) 总被引：1，自引：0，他引：1
Marcos A. Gimenes Catalina R. Lopes Maria L. Galgaro Jose F.M. Valls Gary Kochert 《Euphytica》2002,123(3):421-429
Four A-genome species of the genus Arachis (A. cardenasii, A. correntina, A. duranensis, A. kempff-mercadoi), three B genomes species (A. batizocoi, A. ipaënsis and A. magna),the AABB allotetraploid A. hypogaea (cultivated peanut) and introgression lines resulting from a cross between A. hypogaea and A. cardenasii were analyzed by RFLP. The A genome species (cytologically characterized by the presence of a small chromosome pair ‘A’) were closely similar to each other and shared a large number of restriction fragments. In contrast, the B genome species differed more from one another and shared few fragments. The results of this study indicate that the absence of the small chromosome pair is not a good criterion for grouping species of section Arachis as B genome species, since their genome might be quite distinct from the B genome of A. hypogaea.The lowest genetic variation was detected within accessions of A. duranensis (17 accessions), followed by A. batizocoi (4 accessions) and A. cardenasii (9 plants of accession GKP 10017).The high level of genetic variation found in A. cardenasii might indicate that not all accessions of wild species of Arachis are autogamous, as reported for A. hypogaea. 相似文献
6.
Summary The embryos of a cultivated tetraploid peanut (Arachis hypogaea), a wild diploid species (A. villosa), and their hybrid embryos, which generally abort in nature, were cultured in vitro and the plants have been successfully transferred to the soil. The hybrids showed triploid chromosome number (3x=30). The significance of wide hybridization in peanut-improvement programs is discussed. 相似文献
7.
For the first time in the history of black pepper cultivation, a partly fertile interspecific hybrid having partial resistance
to the dreaded disease Phytophthora foot rot was developed through hybridizing Piper nigrum with the wild species Piper colubrinnum. Hybridity of interspecific progenies was established through morphology, anatomy, cytology, and molecular studies. The hybrid,
whose chromosome number is 2n = 39, is a triploid hybrid between a tetraploid and diploid species. The hybrid designated as
Culture P5PC-1 exhibited distinct anatomical and morphological feature with a large number of long spikes with reduced setting
percentage. The RAPD primers OPE 07 and OPG 08 were identified as hybrid specific molecular markers. Functional evaluation
revealed partial introgression of genes—responsible for Phytophthora foot rot resistance—into the hybrid. This hybrid is considered as a successful breakthrough for introgression of resistance
to the cultivated species Piper nigrum from the wild species Piper colubrinnum. 相似文献
8.
Summary
Kalanchoe blossfeldiana was described by Von Poellnitz in 1935. It is an endemic species of Madagascar where it was discovered in 1924 by Perrier de la Bâthie, who described it as the variety coccinea of K. globulifera. By 1930 living plants had been spread throughout Europe and the United States. At the same time commercial growing was initiated by Blossfeld at Potsdam, Germany. Selection within the species and, from 1939, hybridisation with several other Kalanchoe species yielded cultivars from which many have disappeared. K. blossfeldiana, like two selections, has 2n=34 chromosomes. The remaining cultivars, which are likely of hybrid origin, are polyploids. They are usually tetraploids (2n=ca 68), but in some cases numbers of 2n=72, 75, 84, 85 and 96 have been counted. Polyploidy already occurred in 1939, when the first interspecific cross, in this case with K. flammea (2n=34), was recoreed. Other species which have been crossed with K. blossfeldiana are K. pumila (2n=40), K. grandiflora (2n=34), K. schumacheri (2n=?), K. kirkii (2n=?) and K. manginii (2n=34). 相似文献
9.
Summary Starch gel electrophoresis was used to assess isozyme polymorphism in two Manihot species. Crude extracts were obtained from leaves and pollen. Ten enzymes were examined for their polymorphism in a germplasm collection of 365 cultivated plus 109 wild accessions, mainly from Africa. The inheritance of these enzymes was examined using 13 intra and interspecific progenies. Seventeen polymorphic loci were found for the ten enzyme systems, with 59 alleles. All the markers showed disomic heredity and three linkage groups were identified. 相似文献
10.
The present investigation discusses the scope for transferring of resistance to leaf spot disease incited by Alternaria helianthi from two hexaploid wild species (H. tuberosus and H. resinosus) to diploid cultivated sunflower. Interspecific hybrids produced between sunflower and these two hexaploid species were partially fertile with tetraploid chromosome status. Backcrosses of these interspecific hybrids with cultivated sunflower resulted in the formation of sterile triploid plants. To overcome the problem of sterility and facilitate backcrosses with cultivated sunflower, anther culture of the tetraploid interspecific hybrids was carried out to bring down their chromosome number to diploid status. Anthers from both interspecific hybrids were cultured on basal Murashige and Skoog media supplemented with varying concentrations of organics and the growth regulators benzyladenine and naphthaleneacetic acid. Anthers of interspecific hybrids involving H. resinosus responded well and regenerated through an embryogenic route at a frequency of 98.7%. But in interspecific hybrids with H. tuberosus, anthers formed callus and subsequently regenerated shoots through an organogenic pathway. DNA ploidy analysis of anther culture plants of interspecific hybrids derived from H. tuberosus crosses was carried out to identify plants with desired diploid status. In vitro screening of parents, interspecific hybrids and anther culture plantlets against A. helianthi showed resistance in 68.5% of the anther culture plants of interspecific hybrids from H. tuberosus and in 24.3% of the plants derived from interspecific hybrids involving H. resinosus. 相似文献
11.
Summary With embryo rescue and culture techniques interspecific hybrids have been obtained amongst diploid cultivated (Gossypium arboreum, G. herbaceum) and wild species (G. stocksii, G. anomalum) of cotton. The early abscission of the young bolls was prevented by repeated application of growth regulators followed by the culture of immature hybrid embryos (15 days after pollination). The best growth and development were obtained on modified Murashige and Skoog's medium with supplements. The plants were stouter when the cultures were first incubated in the dark for 15–25 days, followed by exposure to light. The hybrid plants transferred to soil developed further and matured, and were more or less intermediate between their respective parents. 相似文献
12.
There are many wild species of pigeonpea which are endemic to Australia. These wild species are cross incompatible with cultivated
species of Indian origin. Cajanus acutifolius is one such species which does not easily cross with cultivated pigeonpea. Interspecific pollinations lead to hybrid seeds
which were semi-shrivelled. Very few seeds germinated to give rise to F1 plants. Backcrossing the hybrid plants to C. cajan,
the male parent, gave rise to aborting seeds which did not germinate in vivo hence BC1 plants are obtained after saving the
aborting embryos in vitro. BC1 plants showed normal meiotic pairing, but had low pollen fertility. The reasons for embryo abortion and low pollen fertility
in spite of normal meiosis could be due to the effect of wild species cytoplasm.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
13.
A successful interspecific hybridization between cucumber (Cucumis sativus L., 2n = 14) and a wild it Cucumis species, C. hystrix Chakr. (2n = 24) was made via embryo rescue. Hybrid plants (2n = 19; 7 from cucumber and 12 from C. hystrix) were sterile, but morphologically uniform. Self-pollination and backcrossing of F1 hybrid plants to either parent confirmed presence of both male- and female-sterility that were likely caused by lack of homology
and improper pairing during meiosis. While the multiple-branching habit, densely brown hairs (on corolla and pistil), orange-yellow
corolla, and ovate fruit of F1 hybrid plants were similar to that of the C. hystrix parent, the appearance of the first pistillate flower was more similar to that of C. sativus parent. The diameter and internode length of the stem, and the shape and size of leaves and flowers were intermediate when
compared to the parents. The chromosome number in the hybrid was doubled through somaclonal variation during embryo culture
and regeneration process to restore the fertility. Pollen grains were released and fruits with viable seeds matured on fertile,
synthetic amphidiploid plants. The results from flow cytometry indicated that, on average, 7.3% of the morphologically unique
regenerants had the 4C DNA content of 2.35 pg relative to the 2C DNA content of the original F1 hybrid at 1.17 pg and, therefore, were likely chromosome-doubled F1 hybrids (2n = 38). Nutrition alanalysis indicated that the synthetic species had higher protein (0.78%)and mineral (0.35%)
content compared to the normal pickling cucumber(0.62% and 0.27%, respectively), and could be considered a new Cucumis crop having a special place in the future agriculture. Preliminarily evaluation indicates that C. hystrix possesses a high level of root-knot nematode resistance, and that this resistance is partially expressed in the interspecific
F1 and chromosome-doubled F1. This and the fact that the fruit morphology of the fertile amphidiploid differs during the growing season (e.g., short and
long fruit) suggest that it could be useful in broadening the germplasm base of cucumber.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
14.
Summary The levels of the naturally occurring insecticide 2-tridecadone (2TD) were measured in leaves of Lycopersicon hirsutum f. glabratum, L. esculentum, the interspecific F1 hybrid, the F2 and backeross generations. The wild species contains 50 times more 2TD than the cultivated tomato and the frequency distribution of the substance indicates that there is dominance for low levels of the compound. The genotype of F2 plants was determined with respect to 6 codominant isozyme markers and 4 dominant/recessive markers. Significant associations were detected between 5 of the marker genes and the level of 2TD. We interpret these results as implying linkage between marker genes and genes that control the level of 2TD. The behavior of the gene for the determinant growth habit of the plants suggests that it has a pleiotropic effect on the level of 2TD. 相似文献
15.
Summary An interspecific hybridization program designed to transfer gene(s) controlling apomixis from Pennisetum squamulatum Fresen. (2n=6x=54) to induced tetraploid (2n=4x=28) cultivated pearl millet, Pennisetum americanum (L.) Leeke resulted in four offtype plants, two with 27 chromosomes and two with 28 chromosomes. These plants were found among 217 spaced plants established from open-pollinated seed of an apomictic 21-chromosome polyhaploid (2n=21) plant derived from an apomictic interspecific hybrid (2n=41) between tetraploid pearl millet and Pennisetum squamulatum. It appeared that a 21- (or 20-) chromosome unreduced egg from the apomictic polyhaploid united with a 7-chromosome pearl millet (2n=2x=14) gamete to produce a 28- (or 27-) chromosome offspring. Meiotic chromosome behavior was irregular averaging from 3.60 to 4.05 bivalents per microsporocyte in the 27- and 28-chromosome hybrids. The 27- or 28-chromosome hybrids, like the 21-chromosome female parent, shed no pollen, but set from 1.8 to 28 seed per panicle when allowed to outcross with pearl millet. Progeny of the 28-chromosome hybrids were uniform and identical to their respective female parents, indicating that apomixis had been effectively transferred through the egg. In addition, a 56-chromosome plant resulting from chromosome doubling of a 28-chromosome hybrid was identified. Pollen was 68 per cent stainable and the plant averaged 2.3 selfed seeds per panicle. Chromosomes of the 56-chromosome plant paired as bivalents (x=10.67) or associated in multivalents. Three to nine chromosomes remained unpaired at metaphase I. Multiple four-nucleate embryo sacs indicated the 56-chromosome hybrid was an obligate apomict. The production of 27-, 28-, and 56-chromosome hybrid derivatives were the results of interspecific hybridization, haploidization, fertilization of unreduced apomictic eggs, and spontaneous chromosome doubling. These mechanisms resulted in new unique genome combinations between x=7 and x=9 Pennisetum species. 相似文献
16.
Summary Pollen germination and pollen tube growth after self- and intra- and interspecific pollinations of annual [M. scutellata (L.) Mill., M. disciformis DC., and M. rigidula (L.) All.] and perennial (M. sativa L.) Medicago species were studied using a Carl Zeiss microscope with a fluorescence filter attachment.Self-pollination of self-fertile annual and intraspecific pollination of cross-fertile perennials were characterized by high pollen germination and rapid normal pollen tube growth. In contrast pollen germination percentages were very low and many pollen tube growth abnormalities occurred following interspecific pollination and self-pollination of self-sterile plants. The time period from pollination to fertilization for interspecific crosses was about double that following self-pollination of the annual species. However, fertilization occurred frequently following interspecific pollinations. Much of the sterility was due to factor(s) operating after fertilization.Cooperative investigations of the Kansas Agricultural Experiment Station, Dept. of Agronomy and the U.S. Department of Agriculture, Agricultural Research Service. Contribution No. 82-582-J- Mention of a trademark name or proprietary product does not constitute a guarantee or warranty by the U.S. Department of Agriculture, and does not imply its approval over other products that also may be suitable. 相似文献
17.
David M. Spooner Ronald G. van den Berg Willman García María Luisa Ugarte 《Euphytica》1994,79(1-2):137-148
Summary We conducted joint Bolivia/The Netherlands/United States wild potato (Solanum sect. Petota Dumort.) germplasm collecting expeditions in Bolivia from February 1-April 15, 1993, and January 1-February 26, 1994. The goals of the expeditions were to collect germplasm and gather data for continuing taxonomic studies of the approximately 43 taxa of Bolivian wild potatoes accepted by current taxonomists. We made 223 collections, 135 as true seed collections, 54 as tubers, 19 only as herbarium collections. Two recent taxonomic treatments of Bolivian wild and cultivated potatoes have clarified the taxonomy and distribution of these plants, but there are continuing disagreements between treatments regarding species boundaries and interrelationships. These disagreements, and the variability we observed in natural populations, present problems for identifications. We summarize the state of germplasm collections for Bolivia, provide our field data regarding the taxonomy of Bolivian wild potatoes, provide recommendations for future collecting, and provide new chromosome counts for S. hoopesii, S. ugentii, and S. yungasense. 相似文献
18.
Repeat unit length and restriction site variation in ribosomal RNA geneclusters (rDNA) was surveyed in 77 Arachis accessions, includingsamples from 39 accessions of cultivated Arachis hypogaea(2n=4x=40), 36 accessions representing 15 related tetraploid and diploidwild species, and two synthetic amphidiploids. Total genomic DNA wasdigested with five restriction enzymes, and probed with three heterologousribosomal clones of wheat and broad bean. Four rDNA repeat unit lengthclasses were recognized in the Arachis species. Restriction site analysisshowed that some SacI, BamHI and TaqI cleavage sites in rDNA unit werehighly conserved. With few exceptions, the variable BamHI and EcoRV siteswere able to differentiate the taxonomic sections and species, respectively.Arachis hypogaea and A. duranensis accessions produced fourrDNA length classes. Among these, three were identical with those of otherArachis species. A SacI restriction site (s) from probe (Ver6-5) cangenerally distinguish the two subspecies A. hypogaea ssp. hypogaea and A. hypogaea ssp. fastigiata. Forty nine per centof bands were polymorphic across the A. hypogaea accessionsanalysed. This study does not support A. batizocoi to be a progenitorof A. hypogaea. For the gene array, the contribution from eachparental genome can be detected in the two synthetic amphidiploids. 相似文献
19.
G. Ladizinsky 《Euphytica》1979,28(1):179-187
Summary Following hybridization experiments and cytogenetic analysis of interspecific hybrids three chromosome interchanges were found between the cultivated lentil L. culinaris and L. nigricans, and only one between the cultivated species and L. orientalis. This indicates that the latter species is more likely to be wild progenitor of lentil. The partial fertility of the interspecific hybrids indicate further that both L. nigricans and L. orientalis should be included in the wild genepool of lentil, and their variation can be exploited by relatively simple hybridization techniques. The wild lentils L. orientalis and L. nigricans are morphologically very similar but reproductively strongly isolated from one another by the albino seedling of their hybrids. It has been suggested that the populations of L. orientalis that gave rise to the cultivated lentil still possess a similar chromosome arrangement as in L. culinaris and are also capable of forming normal hybrids with L. nigricans. According to these considerations it is unlikely that lentil originated from populations at the south western corner of the distribution area of L. orientalis. 相似文献
20.
Summary Germination of pollen grains and growth of pollen tubes were studied to determine the cause of barreness in crosses among annual Cicer species. In vivo and in vitro time-course studies and fluorescent microscopy revealed no pollination incompatibility among the selfs, crosses and reciprocals of C. arietinum L., C. reticulatum
Lad. and C. cuneatum
Rich. In general, Cicer pollen grains germinated and grew on styles of Cicer species. Pollen tube growth was characterized by irregularly spaced and intermittent callose deposits. Failure of seed formation in interspecific pollinations may be attributed to the slowness of pollen tube growth or collapse of fertilized ovules. In addition to these causes, shortness of stamens and sparsity of pollen grains were responsible for flower drop in natural selfs. Although the number of pollen tubes entering the micropyle in interspecific pollinations was low, it may be possible to grow the fertilized ovules on an artificial medium to obtain F1 plants. 相似文献