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1.
M. Q. Yu    G. B. Deng    X. P. Zhang    X. R. Ma  J. Chen   《Plant Breeding》2001,120(4):285-289
Chromosome pairing was analysed in F1 hybrids of the wheat cultivar ‘Chinese Spring’ (CS) and its ph1b mutant (CSphlb) with Dasypyrum villosum. On average, 1.61 chromosomes per cell paired in the hybrid CS ×D. villosum, but 14.43 in the hybrid CS ph1b×D. villosum. Genomic fluorescence in situ hybridization (GISH) revealed three types of homoeologous association between wheat (W) and D. villosum (D) chromosomes (W‐D, D‐W‐W and D‐W‐D) in pollen mother cells of the CS ph1b×D. villosum hybrid, and only one type (W‐W), in the CS ×D. villosum hybrid. Both F1 hybrids were self‐sterile. The seed set of the backcross of CS ×D. villosum with CS was 6.67% and that of CS ph1b×D. villosum with CS or CS ph1b was only 0.45%. The chromosome number of BC1 plants varied from 48 to 72. Translocations of chromosome segments or entire arms between wheat and D. villosum chromosomes were detected by GISH in the BC1 plants from the backcross of CS ph1b×D. villosum to CS ph1b.  相似文献   

2.
Development of wheat–alien translocation lines has facilitated practical utilization of alien species in wheat improvement. The production of a compensating Triticum aestivum–Thinopyrum bessarabicum whole‐arm Robertsonian translocation (RobT) involving chromosomes 6D of wheat and 6Eb of Th. bessarabicum (2n = 2x = 14, EbEb) through the mechanism of centric breakage–fusion is reported here. An F2 population was derived from plants double‐monosomic for chromosome 6D and 6Eb from crosses between a DS6Eb(6D) substitution line and bread wheat cultivar ‘Roushan’ (2n = 6x = 42, AABBDD) as female parent. Eighty F2 genotypes (L1–L80) were screened for chromosome composition. Three PCR‐based Landmark Unique Gene (PLUG) markers specific to chromosomes 6D and 6Eb were used for screening the F2 plants. One plant with a T6EbS.6DL centric fusion (RobT) was identified. A homozygous translocation line with full fertility was recovered among F3 families and verified with genomic in situ hybridization (GISH). Grain micronutrient analysis showed that the DS6Eb(6D) substitution line and T6EbS.6DL stock have higher Fe and Zn contents than the recipient wheat cultivar ‘Roushan’.  相似文献   

3.
Genetic male sterility (GMS) genes in wheat (Triticum aestivum L.) can be used for commercial hybrid seed production. A new wheat GMS mutant, LZ, was successfully used in the 4E-ms system for producing hybrid wheat, a new approach of producing hybrid seed based on GMS. Our objective was to analyse the genetic mechanism of male sterility and locate the GMS gene in mutant LZ to a chromosome. We firstly crossed male sterile line 257A (2n = 42) derived from mutant LZ to Chinese Spring and several other cultivars for determining the self-fertility of the F1 hybrids and the segregation ratios of male-sterile and fertile plants in the F2 and BC1 generations. Secondly, we conducted nullisomic analysis by crossing male sterile plants of line 257A to 21 self-fertile nullisomic lines as male to test the F1 fertilities and to locate the GMS gene in mutant LZ to a chromosome. Thirdly, we conducted an allelism test with Cornerstone, which has ms1c located on chromosome 4BS. All F1s were male fertile and the segregation ratio of male-sterile: fertile plants in all BC1 and F2 populations fitted 1:1 and 1:3 ratios, respectively. The male sterility was stably inherited, and was not affected by environmental factors in two different locations or by the cytoplasm of wheat cultivars in four reciprocal cross combinations. The results of nullisomic analysis indicated the gene was on chromosome 4B. The allelism test showed that the mutant LZ was allelic to ms1c. We concluded that the mutant LZ has common wheat cytoplasm and carries a stably inherited monogenic recessive gene named ms1g.  相似文献   

4.
Durum or macaroni wheat (Triticum turgidum L., 2n = 4x = 28; AABB) is an allotetraploid with two related genomes, AA and BB, each with seven pairs of homologous chromosomes. Although the corresponding chromosomes of the two genomes are potentially capable of pairing with one another, the Ph1 (Pairing homoeologous) gene in the long arm of chromosome 5B permits pairing only between homologous partners. As a result of this Ph1-exercised disciplinary control, durum wheat and its successor, bread wheat (Triticum aestivum L., 2n = 6x = 42; AABBDD) show diploid-like chromosome pairing and hence disomic inheritance. The Ph mutants in the form of deletions are available in bread wheat (ph1b) and durum wheat (ph1c). Thus, ph1b-haploids of bread wheat and ph1c-haploids of durum wheat show extensive homoeologous pairing that has been shown by us and several others. Here we study the effect of ph1b allele of bread wheat on chromosome pairing in durum haploids, whereas we studied earlier the effect of ph1c allele in durum haploids that we synthesized. In durum wheat, the ph1b-haploids show much higher (49.4% of complement) pairing than the ph1c-haploids (38.6% of complement). Mention of a trademark or proprietary product does not constitute a guarantee or warranty of the product by the USDA or imply approval to the exclusion of other products that also may be suitable.  相似文献   

5.
Summary Intergeneric crosses between Triticum durum-Dasypyrum villosum (2n=42, AABBVV), and Psathyrostachys huashanica (2n=14, N h N h ) were made, the seed set was 1.67%. Intergeneric hybrid were successfully obtained by means of embryo culture for first time. The average chromosome pairing in the hybrid (ABVN h ) was 26.61% univalents, and 0.69 bivalents. The chiasmata per cell was 0.69. The chiasmata was higher than that in Triticum durum dihaploid (AB), and lower than that in T. durum-Dasypyrum villosum trihaploid (ABV). The result indicated that the N h genome of Psathyrostachys huashanica has no homology with the V genome of Dasypyrum villosum, and the A and B genomes of Triticum durum. The coenocytism, micronuclei cell and variation in chromosome numbers were also observed. The F1 hybrid was crossed with Triticum aestivum (AABBDD), and resulted in seed set. The hybrid of T. durum-D. villosum amphidiploid x P. huashanica showed partial fertility. It made the possibility for chromosome manipulation among Triticum aestivum, Dasypyrum villosum and Psathyrostachys huashanica.  相似文献   

6.
The present study evaluated the individual plants reaction of F2 hybrid generation of C. annuum: ATZ1 × PO and ATZ1 × CDT as well as two interspecific hybrids: C. frutescens × C. annuum ATM1 and C. frutescens × C. chinense on androgenesis conditions in in vitro anther cultures. The experiment was carried out following a modified method of Dumas de Vaulx et al. (Agronomie 1:859–864, 1981). There were demonstrated clear differences in the effectiveness of androgenesis both between the pepper hybrid forms as well as among individual plants of all the genotypes tested. The highest effectiveness of androgenic embryos development was observed for the cultivated form of C. annuum: (ATZ1 × PO)F2. Anthers of most of the plants of this hybrid produced embryos at the level higher than 5%, while in anther cultures of the second C. annuum hybrid (ATZ1 × CDT)F2 almost 3-fold fewer embryos and plants were produced. Anthers isolated from flower buds of interspecific hybrids formed much lower number of embryos. A positive reaction was recorded for five hybrid plants of (C. frutescens × C. annuum ATM1)F2, while in case of (C. frutescens × C. chinense)F2 androgenic embryos were obtained from anthers of two plants. Only in the case of a one of these plants did the effectiveness of androgenesis exceed 5%. The ploidy level of the regenerants was determined by flow cytometry. Among the regenerants there were observed both haploid forms and the plants with the diploid number of chromosomes.  相似文献   

7.
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   

8.
New tri-species hybrids (GOS) in the genus Pennisetum involving the cultivated species pearl millet (P. glaucum L.) and two wild species, viz. P. squamulatum Fresen and P. orientale L. C. Rich, are reported. Six hybrid plants were recovered after crossing a backcross hybrid (2n = 3x = 23, GGO) between P. glaucum (2n = 2x = 14, GG) and P. orientale (2n = 2x = 18, OO) with F1s (2n = 6x = 42, GGSSSS) between P. glaucum (2n = 4x = 28, GGGG) and P. squamulatum (2n = 8x = 56, SSSSSSSS). The hybrids were perennial, morphologically intermediate to their parents, and represented characters from the three contributing species. The hybrids contained 2n = 44 chromosomes (GGGSSO) representing 21, 14 and nine chromosomes from P. glaucum, P. squamulatum and P. orientale, respectively. Meiotic and flow-cytometric analysis suggested origin of these hybrids from unreduced female and reduced male gametes. Average chromosome configuration (8.42I + 14.32II + 1.62III + 0.52IV) at Meiosis showed limited inter-genomic pairing indicating absence of significant homology between the three genomes. The hybrids were male sterile (except one) and highly aposporous. P. orientale was identified to induce apospory in hybrid background with P. glaucum at diploid and above levels, though it was quantitatively affected by genomic doses from sexual parent. A case of inducible and recurrent apospory is presented whereby a transition from Polygonum-type sexual embryo-sacs to Panicum-type aposporous embryo-sacs was observed in diploid interspecific hybrids. Results supported independent origin and partitioning of the three apomixis-components (apomeiosis, parthenogenesis, and functional endosperm development), reported for the first time in Pennisetum. Potential utilization of GOS hybrids in understanding genome interactions involved in complex traits, such as perenniality and apomixis, is discussed.  相似文献   

9.
F. Ahmad  A. Comeau 《Plant Breeding》1991,106(4):275-283
New intergeneric hybrids were obtained between Triticum aestivum L. cv. Tukuho’ (2n = 6x = 42, AABBDD) and Agropyron fragile (Roth) Candargy PGR 8097 (2n = 4x = 28, PPPP) at a frequency of 1.06 %, through the use of direct embryo culture and in ovulo embryo culture. Such hybrids could be used to transfer barley yellow dwarf virus (BYDV) resistance and winterhardiness into bread wheat. The somatic chromosome number in all the hybrid plants was 2n = 5x = 35, as expected. Considerable variation in chromosome pairing was observed among the different hybrid plants. Average meiotic chromosome configuration at metaphase I was 17.29 Is + 6.57 rod Us + 1.97 ring Us + 0.18 III + 0.03 IV + 0.002 VI. The high level of chromosome pairing in some F1 hybrids was attributed to Ph-suppressor gene(s) present in A. fragile. The hybrids could not be backcrossed to wheat, but amphiploid seeds have been obtained by colchicine treatment.  相似文献   

10.
Two diploid accessions of wild oat, CIav6956 and CIav7233, were identified as carrying seedling resistance to oat crown rust (caused by Puccinia coronata f. sp. avenae; Pca). Two vigorous interploidy F1 hybrids were generated from crosses involving the hexaploid oat cultivar Wintaroo and the diploid oat Avena strigosa Schreb. accession CIav6956. An additional interploidy F1 hybrid, designated “F1-Aa1”, was produced from a cross of Wintaroo and the diploid oat accession CIav7233. All three hybrids were more vigorous and taller than the cultivated parent Wintaroo. The three F1 hybrids contained full chromosome complements from both parents (2n = 4x = 28), but no seeds were obtained when the three F1 hybrids were selfed. Meiotic analyses of the hybrids indicated that they exhibited a high degree of inter-genome and intra-genome pairing. Trivalent configurations were detected in 95–96% of meiotic cells and a minimum of three bivalents was present in all cells. An average chiasma frequency of 7.2–7.9 per cell was observed for the three F1 hybrids. A fourth F1 hybrid was subsequently generated from a cross between the diploid oat accession CIav7233 and Wintaroo. One octaploid (2n = 8x = 56) was generated from this hybrid and progeny were resistant to two Pca races. The chromosome number of the octaploid progeny varied between 51 and 54 chromosomes. Development of a chromosome addition line(s) with the crown rust resistance should be possible from these partial-octaploids.  相似文献   

11.
Interspecific hybrids were produced from reciprocal crosses between Brassica napus (2n = 38, AACC) and B. oleracea var. alboglabra (2n = 18, CC) to introgress the zero-erucic acid alleles from B. napus into B. oleracea. The ovule culture embryo rescue technique was applied for production of F1 plants. The effects of silique age, as measured by days after pollination (DAP), and growth condition (temperature) on the efficiency of this technique was investigated. The greatest numbers of hybrids per pollination were produced under 20°/15°C (day/night) at 16 DAP for B. oleracea (♀) × B. napus crosses, while under 15°/10°C at 14 DAP for B. napus (♀) × B. oleracea crosses. Application of the ovule culture technique also increased the efficiency of BC1 (F1 × B. oleracea) hybrid production by 10-fold over in vivo seed set. The segregation of erucic acid alleles in the self-pollinated backcross generation, i.e. in BC1S1 seeds, revealed that the gametes of the F1 and BC1 plants carrying a greater number of A-genome chromosomes were more viable. This resulted in a significantly greater number of intermediate and a smaller number of high-erucic acid BC1S1 seeds.  相似文献   

12.
N. Inomata 《Euphytica》2003,133(1):57-64
The cytogenetic study was investigated in the intergeneric F1 hybrid, F2and backcross progenies (BC1). The plants used were Brassica juncea(2n=36) and Diplotaxis virgata(2n=18). Three intergeneric F1 hybrids between two species were produced through ovary culture. They showed 36 chromosomes. It might consist one genome of B. juncea and two genomes of D. virgata. The morphology of the leaves resembled that of B. juncea. The color of the petals was yellow that was like in D. virgata. The size of the petal was similar to that of B. juncea. The mean pollen fertility was15.3% and the chromosome associations in the first meiotic division were(0–1)IV+(0–2)III+(8–12)II+(12–20)I. Many F2 and BC1seeds were harvested after open pollination and backcross of the F1 hybrids withB. juncea, respectively. The F2seedlings showed different chromosome constitutions and the range was from 28 to54 chromosomes. Most seedlings had 38chromosomes followed by 36, 40 and 54. The BC1 seedlings also showed different chromosome constitutions and the range was from 29 to 62. Most seedlings had both 40and 54 chromosomes followed by 36, 46 and52. In the first meiotic division of F2 and BC1 plants, a high frequency of bivalent associations was observed in all the various kinds of somatic chromosomes. Many F3 and BC2 seeds were obtained by self-pollination and open pollination of both F2 and BC1 plants, and by backcrossing both F2 and BC1plants with B. juncea, respectively,especially, three type progeny with 36, 40or 54 chromosomes. The somatic chromosomes of the F3 and BC2 plants were further investigated. The bridge plants between B. juncea and D. virgata with 36 chromosomes may be utilized for breeding of other Brassica crops as well as B. juncea. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

13.
Wei Zhu  Kui Liu  Xue-De Wang 《Euphytica》2008,164(1):283-291
Leaf shape is an important factor affecting canopy structure, photosynthetic characteristics, and yield. Introducing okra leaf shape is considered an important strategy in cotton heterosis breeding. The objective of the study was to evaluate the heterosis in okra leaf cotton hybrid F1s, which were developed by crossing two sterile near isolines and three restorer near isolines. A normal leaf check hybrid F1, Zhongza 29, and four newly developed okra leaf oriented hybrid F1s, including the super-okra (severely cleft and narrowly lobed leaf), okra (deeply cleft and narrowly lobed leaf), semi-okra (intermediate leaf lobe), and sub-okra (large leaf lobe) hybrids were selected in this experiment. Okra leaf oriented cotton hybrids significantly reduced leaf area index (LAI) (P < 0.0001), thus more light penetrated into the lower canopy. The LAIs for the super-okra and okra hybrids, however, were too small to supply adequate photosynthate, thus resulting in early maturity, short boll filling period, and low yield. As the LAI increases, the semi-okra and sub-okra hybrids showed certain heterosis. The semi-okra hybrid showed 7–12% heterosis over the check hybrid in lint percent, 6–11% in boll weight, 2–147% in canopy light intensity, 1–10% in net photosynthetic rate (Pn), and −3 to 3% in lint yield. As well, all tested okra leaf hybrids improved fiber quality such as micronaire compared with the normal leaf check hybrid. The results suggested that adopting okra leaf parental lines in cotton breeding provided potentials in increasing fiber quality with comparable lint yield.  相似文献   

14.
Dasypyrum villosum (L.) Candargy is a diploid, wild relative of bread wheat (Triticum aestivum L.). Previous studies showed that D. villosum chromosome 1V has genes that encode seed storage proteins that may be used to enhance the grain quality of bread wheat. As a first step in genetic transfer, the present study was initiated to develop compensating Robertsonian translocations involving wheat chromosome 1D and D. villosum chromosome 1V and to analyze their effects on grain quality. A monosomic 1D stock was crossed with the disomic addition stock DA1V#3 and the double monosomic plants (20″ + 1D′ + 1V#3′) were self pollinated. Two co-dominant STS markers (BE499250 and BE591682) polymorphic for the short arm of 1V#3S and two dominant STS markers (BE518358 and BE585781) polymorphic for the long arm of 1V#3L were developed to screen a large number of progeny to identify plants that had only the 1V#3S or 1V#3L arms. Five compensating Robertsonian heterozygous translocations, two (plants #56 and #83) for the short arm (T1DL·1V#3S) and three (plants #7, #123, and #208) for the long arm (T1DS·1V#3L) were identified from 282 F2 plants and confirmed by genomic in situ hybridization and C-banding analyses. Two homozygous translocations T1DL·1V#3S (plants #14 and #39) were identified from 52 F3 plants derived from F2 plant #83. Four homozygous translocations T1DS·1V#3L (plants #3, #22, #29, and #30) were identified from 68 F3 plants derived from F2 plant #208. The homozygous translocation T1DL·1V#3S had a significantly higher (37.4 ml) and T1DS·1V#3L had significantly lower (10 ml) Zeleny sedimentation values compared to Chinese Spring wheat (30.7 ml). Our results showed that 1V#3S increased gluten strength and enhanced wheat quality, but 1V#3L decreased gluten strength and did not enhance wheat quality.  相似文献   

15.
Interspecific hybrids Buddleja davidii × Buddleja weyeriana, Buddleja weyeriana × Buddleja davidii and Buddleja davidii × Buddleja lindleyana were generated using in vitro embryo rescue 10–11 weeks after manual pollination. The morphological variation within the F1 populations was limited. The F1 progeny of B. davidii × B. lindleyana was almost sterile and no F2 generation was obtained. From the other hybrids, F2 generations were made by self pollinations and back crosses. Hybrid nature of all F1 and F2 seedlings was confirmed by AFLP. Chromosome counting and genome size measurement for B. weyeriana (F2 selection of (diploid) B. globosa × (tetraploid) B. davidii) revealed a higher chromosome number (76 chromosomes) and genome size than expected, indicating 2n-gametes formation occurred during meiosis of B. globosa. The F1 hybrids B. weyeriana × B. davidii (76 chromosomes) had an intermediate genome size compared with the genome size of the parent plants, proving their hybrid nature. However, the F1 and F2 hybrids of B. davidii × B. weyeriana all had 76 chromosomes but had a lower genome size than expected, suggesting the occurrence of chromosome rearrangements in the genome of the hybrids. B. lindleyana had 38 chromosomes, while the F1 hybrids of B. davidii × B. lindleyana had 76 chromosomes. Also genome size measurements revealed that the F1 seedlings B. davidii × B. lindleyana had higher genome sizes than expected. Both the results of chromosome counting and genome size measurement indicate that 2n-gametes formation took place during meiosis of B. lindleyana.  相似文献   

16.
An intraspecific (Tetir × ILL 323) and an interspecific (Alpo × L. odemensis) lentil hybrid were multiplied in vitro in three consecutive micropropagation cycles to increase the production of F2 seeds. Cloning efficiencies were slightly higher for Tetir × ILL323 (83%) compared to Alpo × L. odemensis (67%). A total of 982 F2 seeds were produced in the experiment with Alpo × L. odemensis, consisting of the 334 F2 seeds of the original hybrid and 648 F2 seeds produced by the 12 plants cloned; consequently, F2 seed production was increased three-fold over the original hybrid (194%). A total of 6050 F2 seeds were produced in the experiment with Tetir × ILL 323, made up of the 483 F2 seeds of the original hybrid and 5567 F2 seeds produced by the 15 plants cloned; therefore, F2 seed production was increased by more than twelve-fold over the original hybrid (1153%). In both hybrids the F2 seed production of cloned plants diminished in the three consecutive multiplication cycles, with the plants having experienced less vegetative development. In lentil, F2 seed production of cloned plants is related for the first time to the length of their period of vegetative development. In conclusion, micropropagation of hybrids is an interesting tool to construct from a single individual large F1 populations that enable to increase by a manifold the production of F2 seeds useful for genetic studies and breeding.  相似文献   

17.
Summary Crosses between a wild species C. chacoense and three cultivated species of chili pepper viz. C. annuum, C. frutescens and C. chinense yielded hybrids when C. chacoense was the seed parent but the reciprocal crosses were unsuccessful. C. chacoense × C. annuum F1 hybrids were partly fertile and therefore an F2 population could be raised; the other two F1 hybrids were totally sterile. Chromosome pairing in the F1 plants resulted largely in bivalents and a few multivalents and univalents. The genomes of the four species share large homologies and the role of chromosome structural changes in genome differentiation is suggested. Hybrid sterility is the major reproductive isolation mechanism.  相似文献   

18.
Zea mays ssp. mexicana, an annual wild relative of maize, has many desirable characteristics for maize improvement. To transfer alien genetic germplasm into maize background, F1 hybrids were generated by using Z. mays ssp. mexicana as the female parent and cultivated maize inbred line Ye515 as the male parent. Alien introgression lines, with a large range of genetic diversity, were produced by backcross and successive self-pollinations. A number of alien introgression lines with the predominant traits of cultivated maize were selected. Genomic in situ hybridization (GISH) proved that small chromosome segments of Z. mays ssp. mexicana had been integrated into the maize genome. Some outstanding alien introgression lines were evaluated in performance trials which showed 54.6% hybrids had grain yield greater than that of hybrid check Yedan12 which possessed 50% Ye515 parentage, and 17.1, 9.9% hybrids had grain yield competitive or greater than those of Nongda108 and Zheng958, which were elite commercial hybrids in China, respectively. The results indicated that some of the introgression lines had excellent agronomic traits and combining ability for maize cultivar, and demonstrated that Z. mays ssp. mexicana was a valuable source for maize breeding, and could be used to broaden and enrich the maize germplasm.  相似文献   

19.
Summary The possibilities to transfer important traits and in particular resistance to the beet cyst nematode (Heterodera schachtii, abbrev. BCN) from Raphanus sativus to Brassica napus were investigated. For these studies B. napus, R. sativus, the bridging hybrid ×Brassicoraphanus (Raparadish) as well as offspring of the cross ×Brassicoraphanus (Raparadish) ×B. napus were used. Reciprocal crosses between B. napus and R. sativus were unsuccessful, also with the use of embryo rescue. Crosses between ×Brassicoraphanus as female parent and B. napus resulted in a large number of F1 hybrids, whereas the reciprocal cross yielded mainly matromorphic plants. BC1, BC2 and BC3 plants were obtained from backcrosses with B. napus, which was used as the male parent. F1 hybrids and BC plants showed a large variation for morphology and male and female fertility. Cuttings of some F1 and BC1 plants, obtained from crosses involving resistant plants of ×Brassicoraphanus, were found to possess a level of resistance similar to that of the resistant parent. These results and indications for meiotic pairing between chromosomes of genome R with those of the genomes A and/or C suggest that introgression of the BCN-resistance of Raphanus into B. napus may be achieved.  相似文献   

20.
Hot pepper is the most important worldwide grown and consumed spice and vegetable crop. Though hybrid breeding has been proposed for genetic improvement in the crop, but there is lack of information on heterosis in crosses among crop genotypes in Ethiopia. Twelve genotypes (nine Asian and three Ethiopian parents) of hot pepper were crossed in 2003 cropping season in a half-diallel fashion to fit Griffing’s fixed effect model analysis. An open field experiment was conducted in 2004/2005 to investigate heterosis for fourteen traits in 66 F1 hybrids grown together with their 12 selfed parents. Highly significant genotypic differences were observed for all the traits except for leaf area. Variance component due to specific combining ability (dominance) were larger than that due to general combining ability (additive) for each of the studied traits with few exceptions. Broad sense heritability (H b2) for fruit traits were more than 60% and with wide gap from narrow sense heritability (h n2) for most of the important traits like number of fruit per plant (H b2 = 88.3% and h n2 = 46.0%), days to maturity (H b2 = 87.2% and h n2 = 23.1%) and dry fruit yield per plant (H b2 = 72.6% and h n2 = 14.6%). Maximum heterosis over mid-parent and better-parent, and economic superiority of hybrid over standard check were recorded, respectively for dry fruit yield per plant (163.8, 161.8 and 92.1%), number of fruits per plant (104.4, 79.6 and 136.4%) and days to maturity (−29.8, −31.5 and −23.6%). These observations suggested a possibility of utilizing dominance genetic potentiality available in diverse genotypes of the crop by heterosis breeding for improving hot pepper to the extent of better economic return compared to the current commercial cultivar under production in the country. Low narrow sense versus very high broad sense heritability for days to maturity and dry fruit yield per plant could be a sign for achievability of earliness and high fruit yield using heterosis in hot pepper. The maximum heterobeltiosis were recorded either from F1s obtained from Ethiopian and Asian crosses or from within Asian crosses, suggesting the possibility of maximizing heterosis by considering genetically diverse parental genotypes. The manifestation of highest heterosis in hybrids from among Asian lines indicated existence of genetic diversity among Asian genotypes and the potentiality for improvement of hot pepper using genotypes from different regions of the world along with elite inbred lines from local cultivars.  相似文献   

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