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1.
Crosses between pearl millet lines and Pennisetum ramosum, P. schweinfurthii, P. squamulatum or Cenchrus ciliaris were observed for the frequency and development of zygotes, the possibility of embryo rescue, and the fertility of F1 hybrids obtained. Eight per cent of the ovules from diploid millet × P. ramosum crosses showed small embryos which could not be rescued. However, 59% of the ovules from tetraploid millet × P. ramosum crosses showed well-developed embryos that were easy to rescue 14 days after pollination. F1 hybrids were male sterile but female fertile when pollinated by diploid millet. Both diploid and tetraploid millet ovules showed the presence of hybrid zygotes after pollination with P. schweinfurthii at rates ranging from 25% to 45%. The diploid millet× P. schweinfurthii hybrid zygotes often developed almost normal seeds giving, without embryo rescue, totally sterile plants. The tetraploid millet × P. schweinfurthii hybrid embryos were normal but the endosperm was severely defective. A hybrid obtained by embryo rescue was totally sterile. A diploid millet-P. schweinfurthii amphidiploid was obtained by somatic embryogenesis associated with colchicine treatment during callogenesis. This amphiploid plant was male sterile, but gave many seeds when pollinated by a tetraploid millet and few seeds when pollinated by a diploid millet. P. squamulatum pollinating diploid millets produced proembryos with large undifferentiated endosperms in 73% of the ovules. A normal seed set was observed on tetraploid millets pollinated by P. squamulatum and the resulting F1 hybrids were partially male and female fertile. Backcrosses of these hybrids were much more fertile when pollination was from a tetraploid millet rather than from a diploid millet. C. ciliaris pollinating a diploid millet showed, in 60% of the ovules, proembryos and endosperms similar to those observed with P. squamulatum and no hybrid could be rescued. Crosses with a tetraploid millet could not be attempted due to the pistil-pollen incompatibility of tetraploid millets available with C. ciliaris. Ploidy levels of mating partners do not seem to influence pistil-pollen compatibility, but play a major role in post-zygotic abortion. With adequate ploidy levels of parents, and embryo rescue, it seems that the pearl millet gene pool can be considerably enlarged by germplasm from many other species. 相似文献
2.
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
3.
Kesara Anamthawat-Jónsson Sigrídur K. Bödvarsdóttir Birkir Th. Bragason Jón Gudmundsson P.K. Martin R.M.D. Koebner 《Euphytica》1997,93(3):293-300
A total of 240 F1 hybrids was made beween wheat (Triticum aestivum L. em. Thell. (2n = 6x = 42) and T. carthlicum Nevski (2n = 4x = 28)) and
perennial lymegrass (North European Leymus arenarius (L.) Hochst. (2n = 8x = 56) and North American L. mollis (Trin.) Pilger
(2n = 4x = 28)). The wide crosses yielded embryos in 20% of caryopses and 96% of the embryos developed into normal hybrid
plants. The hybrids were vegetatively vigorous, with evidence of the Leymus rhizomatous habit. Those deriving from L. arenarius
survived overwintering in Iceland, but the hybrids L. mollis did not, whereas in a milder environment, both showed perenniality.
Cytogenetic analysis of root tip cells before the plants were treated with colchicine showed that 21 out of 28 hybrids investigated
had chromosome mosaics, with a population of both amphihaploid and amphidiploid cells. This spontaneous doubling of somatic
chromosomes occurred in all cross combinations, with the highest average frequency of diploid cells (28%) in T. carthlicum
× L. arenarius crosses. A few selfed seeds have been obtained from a T. aestivum × L. arenarius hybrid. All the hybrids were
treated twice with colchicine, but the treatment appeared to have little or no effect on the frequency of chromosome doubling
in the hybrids deriving from T. aestivum. The frequency of diploid cells, however, increased significantly (e.g. to 80%) in
the hybrids deriving from the T. carthlicum parent. Genomic in situ hybridization confirmed the hybridity of the plants and
showed that the hybrids were amphiploids containing genomes of both wheat and lymegrass. In situ hybridization using ribosomal
DNA probe differentiated chromosomes of L. mollis, L. arenarius from those of wheat. The hybrids are being backcrossed with
lymegrass pollen, aiming to domesticate the wild, perennial species.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
4.
《European Journal of Agronomy》1999,10(1):9-21
The effects of different nitrogen supplies on the performance of the short-day cultivar M9D3 of pearl millet (Pennisetum glaucum L. R.Br.) and their interaction with sowing time were analysed in a two-year experiment in Mali. The first sowing dates coincided with the beginning of the rainy season. The second sowings were 20 days later. The sowing date affected only the emergence-earing duration independently of nitrogen application. The linear reduction in straw yield, caused by the shortening of the cycle, was not combined with a reduction in grain yield. The application of even low levels of nitrogen to millet crops always increased the grain yield, as a consequence of a higher number of productive panicles, while the straw production was positively affected only when the rainy season started early. The non-agreement between the high productive potential of the first sowing crops and their grain yield, in comparison with the plants of the second sowing date, could be ascribed, first of all, to the more marked asynchrony between the time corresponding to LAImax and the grain filling phase, characterised by the maximum sink demand and, second, to a longer time interval during which stem growth and panicle growth are in direct competition. 相似文献
5.
Summary Successful widespread use of a forage or biomass plant depends largely on its ease of establishment. Elephantgrass (Pennisetum purpureum Schum.) is used for both forage and biomass production, due to its high dry matter production, aggressiveness, perenniality, and forage quality. However, lack of high quality seed has limited the use of elephantgrass and its hybrids to pearl millet (P. glaucum L. R.Br.). Development of a seed-propagated pearl millet x elephantgrass hexaploid cultivar, which would combine desirable characteristics from both of these species, would be highly desirable. The objectives of this study were to characterize morphological and seed-related traits from the selfed progeny of seven hexaploid hybrids, and to determine whether seed size had any influence on these traits. Traits studied included number of tillers, height, leaf length and width, panicles per plant, days to flowering, panicle length, seed set, seed production, and weight of 100 seeds. Genetic differences were found among the progeny of the seven hybrids. Differences were also found between plants derived from large- and small-seed lots within families. Plants descended from larger seed had better growth and seed-related characteristics, which resulted in more desirable plants. These hexaploid hybrids showed potential for direct seeding into the field for biomass or forage production. 相似文献
6.
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
7.
P. J. Lynch 《Plant Breeding》1994,113(3):237-241
Inadequate stand establishment can be a major constraint to high grain and fodder yields of pearl millet (Pennisetum glaucum [L.] R. Br.) in the semi-arid tropics. In this study, two laboratory screening procedures designed to improve components of stand establishment were evaluated. In the first procedure the ability of seedlings to emerge from the soil at 45 °C was tested and in the second procedure the ability of seeds to germinate at 45°C was measured. Two cycles of recurrent selection were conducted with each procedure in the Higrop and Senpop pearl millet gene pools. The resultant populations were evaluated to measure the efficacy of the screening procedures. Selection for increased emergence was effective in the Cc of Higrop. When emergence percentage was averaged across Higrop and Senpop, recurrent selection increased emergence percentage by 7.4 % per cycle. In future, the size of the emergence screening units and number of seeds screened per progeny tested should be increased. The germination selection procedure was ineffective. 相似文献
8.
9.
Pearl millet ( Pennisetum glaucum L.R.Br.) hybrid MH 179 was grown under two moisture regimes viz., optimal moisture and rainfed conditions. The field experiment was continued for three consecutive rainy seasons to quantify the pearl millet development with thermal time. The possible influence of variation in natural sowing date on the relationships between crop development and thermal time have been described. At cardinal temperatures of 10°C (base temperature below which pearl millet development ceases), 33°C (optimal temperature for development) and 45°C (maximum temperature at and above which no development takes place), the crop required 1490–1794°Cd thermal time to reach physiological maturity. The thermal time requirement for different developmental stages was influenced by the sowing time and moisture availability during the growing season of the crop.
The leaf tip appearance on the main shoot of pearl millet in relation to thermal time was almost linear under both moisture conditions requiring about 44–50°Cd ± 2.6 °Cd leaf−1 , till the appearance of the flag (last) leaf. However, leaf tip appearance on primary tillers was slightly slower and required 53-58°Cd ± 4.7°Cd for each new leaf. Appearance of first primary tiller was later (at 320°Cd after emergence) under the rainfed condition as compared to the crop under the optimal moisture (at 250°Cd).Thereafter, the tiller appearance in relation to thermal time under both moisture conditions was at a linear rate of about 53-56°Cd ± 9.5°Cd tiller−1 .
Effect of microclimatic variations, canopy temperature, radiation and photoperiod on the phenology-thermal time relationships have been discussed under both the moisture conditions. 相似文献
The leaf tip appearance on the main shoot of pearl millet in relation to thermal time was almost linear under both moisture conditions requiring about 44–50°Cd ± 2.6 °Cd leaf
Effect of microclimatic variations, canopy temperature, radiation and photoperiod on the phenology-thermal time relationships have been discussed under both the moisture conditions. 相似文献
10.
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
11.
Summary Physiological and morphological characteristics of the two wild and three domesticated subspecies of cowpeas are compared. The wild accessions are alike in having small, hard seeds borne in dehiscent pods, but differ in other characteristics. We suggest that the wild subsp. dekindtiana, from the seasonally-arid tropics, is more likely to have been the progenitor of modern cowpeas than the other wild subspecies (subsp. mensensis), but that subsp. dekindtiana was first cultivated in the humid tropics where its pods are slow to dehisce. Domestication has been associated with changes in the structure of pod valves and seed coats which reduce pod dehiscence and seed hardness. Pods and seeds have increased in size, mainly by increases in the rate of dry weight accumulation, and their increase has been only partly paralleled by increase in the area of subtending leaves. There has been no increase in the maximum photosynthetic rate of leaves, but the duration of their photosynthetic activity has increased. Domesticates are less sensitive than are wild plants to some environmental controls, such as in the response of germination to temperature, but in their flowering responses to daylength both wild and cultivated forms retain sensitivity under conditions where this is of adaptive value. 相似文献
12.
The effect of priming sorghum and pearl millet seeds with fertilizers was investigated. Two experiments were conducted on M35–1 (sorghum) and ICMH 356 (pearl millet), and ICSV 745 (sorghum) and Barmer (pearl millet) seeds, respectively. Treatments included nitrogen, phosphorous and potassium-based treatments which showed that 7.5 g l−1 of urea substantially enhanced the final germination percentage of seeds. The second experiment included 10 priming treatments with 7.5 g l−1 urea mixed with other fertilizers. Results indicated that soaking seeds for 3 days in urea + one of several fertilizers including N, P or K-based nutrient compositions or micro elements significantly increased germination percentage and speed but did not affect seedling growth at 15 or 60 days after sowing. It is concluded that seed priming treatments with fertilizers may serve as an appropriate treatment for advancing germination of the species studied. 相似文献
13.
目前谷子杂交种所用不育系大多属于高度雄性不育系,有5%~10%的自交结实率,因此谷子两系杂交种会有一定比例的假杂种。传统去除假杂种方法是在苗期喷施除草剂去假留真。为了研究更简便、安全、有效去除假杂种的方法,选用拿捕净和咪唑乙烟酸2种除草剂,2019年设置6个浓度（0.2%、0.4%、0.6%、0.8%、1.0%和1.4%）的除草剂药液浸泡种子,筛选最佳浓度;采用阴干、晒干和烘干3种方式,筛选最佳干燥种子方法;2020年把除草剂配入包衣剂对杂交种进行包衣试验,2种除草剂分别设置6个和3个浓度配比。结果表明,采用药液浸泡法时,2种除草剂均采用0.8%浓度最佳,种子均匀沾上药液后捞出阴干或烘干较好。采用包衣方法时,长杂谷466（抗拿捕净类型杂交种）采用“50g包衣剂拌4~5mL拿捕净包衣2.5kg种子”、长杂谷2922（抗咪唑乙烟酸类型杂交种）采用“50g包衣剂拌3mL咪唑乙烟酸包衣2.5kg种子”的方法最佳。 相似文献
14.
Summary Foxtail millet (Setaria italica L. P. Beauv.) has been one of the most important cereals in northern China. A large number of landraces have formed under natural and man-made selection since domestication. Farmers in China have developed various traditional methods of maintenance and multiplication of foxtail millet seeds for next generation. Panicle selection was often done in fields. The selected seeds were generally stored at dry places. Archaeological and historical evidence of the origin of foxtail millet in China and the geographical distribution of landraces is also presented. 相似文献
15.
Shoot and root growth and plant dry weight were determined for twenty four accessions of pearl millet, Pennisetum americanum (L.) Leeke, after two weeks growth in saline solution culture at EC 20 dS m-1. The EC was achieved using NaCl + CaCl2 1:1 by weight in solution culture. Although salinity markedly inhibited growth of all accessions, three, 93613, KAT/PM-2 Kitui, and Kitui local produced significantly greater dry matter, and they and 93612 had longer shoots than the other accessions. Accessions WCA 78 and Bulk 7704 were highly sensitive to salinity in all 3 characters measured. There was considerable variation between the 24 accessions, suggesting that selection for increased tolerance to salinity in pearl millet should be possible. This was examined using normal seed of the cultivar Al/3. A first cycle of selection screened 16,000 seeds after 15 days growth in nutrient solution at EC 26 dS m-1. 106 individuals were selected to form the S1 selection line. Selected seedlings were grown to maturity and polycrossed. In a second cycle of selection, 30,000 S1 polycross progeny were screened as previously, but at EC 30 dS m-1. A selection intensity of 0.08% was achieved. The selected plants were again grown to maturity and again polycrossed. Efficiency of the selection procedure was assessed from comparison in sand culture of the performance of the selected line with the unselected Al/3 line and Kitui local which from the previous assessment of the 24 accessions was rated as relatively salinity tolerant. The selection line was superior to the other two lines at four salinity levels. The results of this study suggest that further improvement in salinity tolerance in pearl millet may be expected from further selection and breeding, using the methods described here. 相似文献
16.
Summary Effect of A1 male sterile cytoplasm on smut severity in pearl millet (Pennisetum glaucum (L.) R.Br.) was studied by comparing 35 pairs of F1 hybrids, each pair carrying male sterile and normal cytoplasm. Mean smut severity was not significantly different in the hybrids carrying male sterile or normal cytoplasm. This suggests that in pearl millet male sterile cytoplasm is not associated with higher smut susceptibility. Partitioning of variance into different components showed that pollinators, A/B line pairs and their interaction primarily influenced smut severity of hybrids. Smut susceptibility might be attributed to effects of cytoplasm × nuclear interactions. 相似文献
17.
Nobumichi Inomata 《Euphytica》1993,69(1-2):7-17
Summary Crossability and cytology were examined in F1, F2, B1 and hybridsplants of F1 hybrids of Brassica campestris and three wild relatives of B. oleracea, B. bourgeaui, B. cretica and B. montana, respectively. The F2 plants were obtained after self-and open pollination of the F1 hybrids. The B1 and hybrid plants were produced after the F1 hybrids backcrosses with B. campestris and crossed with B. napus, respectively. After crossing the F1 hybrids, many seeds of the F2, B1 and hybrid plants were harvested. Multivalent formation was high in the chromsome configuration for the PMCs of F2, B1 and hybrid plants, suggesting that crossing over might occur between them. Many different types of aneuploids were obtained in the progenies of the F2, B1 and hybrid plants. It is suggested that different types of normal egg cells may be produced by one-by-one or little-by-little chromosome addition. The possibility is discussed of gene transfer from B. bourgeaui, B. cretica and B. montana, to cultivated plants, B. campestris and B. napus. 相似文献
18.
Summary To determine the distribution and geographic specificity of sterility maintainers in pearl millet, Pennisetum americanum (L.) Leeke, 428 diverse pearl millet germplasm accessions representing variation from 12 countries were crossed with a male-sterile line 5141A. The F1 hybrids were classified as male-fertile or male-sterile based on the seed set on bagged ear heads and an other morphology. Among these, 87 (20.3%) were classified as male-fertile, 32 (7.5%) as male-sterile, 282 (65.9%) as segregating for male-fertile/male-sterile and 27 (6.3%) behaved as male-fertile in the rainy and male-sterile in the postrainy season. Restorer lines were distributed in all the countries studied except Cameroon and USSR. Maintainer lines were observed from six countries but were concentrated in India. These maintainer lines differ from one another in several morphological and agronomic characters such as flowering, plant height, spike length and grain size. They may prove to be useful sources of material for generating new male-sterile lines. The restorers can be used to produce commercial hybrids.Submitted as J.A. No. 719 by the International Crops Research Institute for the Semi-Arid Topics (ICRISAT). 相似文献
19.
Successful selection of interspecific hybrid progenies with superior ability to regenerate shoots from apical meristems was
performed in sunflower which now allows for the development of lines for improved biotechnological applications. Early generations
of interspecific hybrids originating from crosses between the two H. annuus CMS lines ‘HA89’ and ‘Baso’, and 9 wild species were screened for their ability to regenerate in vitro. Evaluation of 36 progenies allowed to identify seven progenies from crosses involving H. mollis, H. giganteus, H. strumosus, and H. decapetalus which showed a significantly higher regeneration potential than the commercial hybrid ‘Albena’ regarding the number of shoots
per explant. Among these progenies, 47.2 to 62.4% of explants produced shoots with an average of 2.3 to 3.5 shoots per cultured
explant. Regeneration in vitro was significantly determined by the genotype. More than half of the investigated interspecific hybrids performed better than
the inbred ‘HA89’ demonstrating that the high regeneration potential available in the wild species can be efficiently transferred
to cultivated sunflower. The seven progenies with high regeneration potential in vitro were characterised by agronomic performance in the field. Two of the interspecific hybrids derived from H. strumosus and H. decapetalus not only showed a superior regeneration potential but also proved to be competitive to commercial hybrids with regard to
important agronomic traits, e.g. fat content and TGW.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
20.
Summary The occurrence of seed malformation in association with reduced thousand grain weight and germination ability has been observed in crosses between cultivated female plants and wild male plants. A survey of 16 cultivated accessions (P. glaucum subsp. glaucum) and 11 wild accessions (P. glaucum subsp. monodii) ranging over the whole species diversity showed this postzygotic incompatibility was general, but its intensity varied greatly with the cultivated female accession used and very little with the wild male parent origin. About 15% of the 123 cultivated x wild crosses observed gave normal seeds. Seed malformation has never been observed in crosses between cultivated accessions and appeared independent of genetic distances between the parents. The reciprocal crosses between wild female plants and cultivated male plants gave normal-looking seeds with good germination but consistently reduced thousand grain weight. Both seed malformation and seed small size are an expression of a genetic imbalance. These slight reproductive barriers seem to have been built during the domestication process.Abbreviation ICRISAT
International Crop Research Institute for the Semi-Arid Tropics 相似文献