Analysis of genetic variation in Cucurbita moschata by random amplified polymorphic DNA (RAPD) markers (original) (raw)
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Journal of the American Society for Horticultural Science, 2002
A molecular and morphological marker map would improve our knowledge of Cucurbita genetics, and would facilitate efforts to breed improved summer and winter squash cultivars. Random amplified polymorphic DNA (RAPD) markers were used to construct a partial map of the Cucurbita genome. The mapping population was the BC1 progeny of the Cucurbita pepo L. yellow straightneck inbred A0449 and the tropical Cucurbita moschata Duchesne ex Lam. landrace `Nigerian Local'. A0449 was the recurrent parent. This cross was chosen because of the relatively greater economic importance of summer squash, traits of value to be introgressed from the C. moschata parent, and maximized genetic variation from the interspecific cross. The map contains 148 RAPD markers in 28 linkage groups. Loci controlling five morphological traits were placed on the map. The map covers 1,954 cM, which is estimated to be 75% of the Cucurbita genome. The qualitative traits placed on the map include the B gene for fruit whi...
International Journal of Plant & Soil Science
Thirty diverse landraces of pumpkin comprising from eight districts of Assam viz., four landraces from each district, Sivasager, Dibrugarh, Karbi Anglong, Haflong, Jorhat & Majuli and three landraces from each Lakhimpur and Kokrajhar. The landraces were subjected to analyses of variance and covariance for estimation of genetic variability parameters and correlation coefficients among the 19 characters. The experiment was carried out during the rabi season of 2017-18 at the Instruction Cum and Research (ICR) Farm of Assam Agricultural University in a Randomized Block Design with three replications. From the analysis of variance, it was recorded that the presence of variation among thirty pumpkin landraces for all characters. The highest genotypic coefficient of variation (GCV) and phenotypic coefficient of variation (PCV) was recorded for single fruit weight with 51.47 per cent and 54.88 per cent, indicating presence of greater variability for the trait. The heritability in the broad...
Genetic Variability and Inter-Relationship among some Nigerian Pumpkin Accessions (Cucurbita spp
Ten Nigerian pumpkin accessions were evaluated during the 2007 and 2008 planting seasons to estimate the magnitude of genetic variability and the character association among some yield characters. The results revealed wide genetic variability among the accessions. The genotypic and heritabilty estimates were high in days to 50% emergence, days to 50% flowering, fruit diameter and number of seeds/fruit in both planting seasons. However, genotypic and heritability estimates were low in number of male and female flowers at both planting seasons. At both plantings, the number of seeds/fruit had a significant (P < 0.01) positive correlation with the number of male flowers/plant and fruit diameter. A significant positive correlation was also obtained between the number of female flowers and the number of fruits/plant in both planting seasons, an indication that both traits increased or decreased simultaneously. Thus, increasing the number of female flowers would favour fruiting in pumpkin. In both planting seasons, path analysis revealed that days to 50% flowering had the highest positive direct effect on fruit weight and also, had a high direct contribution to the fruit yield. The significant positive correlation between the weight of harvested fruits and fruit diameter in the 2007 planting season was due to the combination of the direct and indirect effects of fruit diameter to fruit yield. In 2008 planting, the number of female flowers recorded high positive direct effects on the weight of fruits/plant but its influence was nulified by the high negative indirect effects (-0.46) of number of fruits/plant. The results indicated that days to flowering, fruit diameter and number of seeds/fruit can be used as selection criteria to increase fruit yield in Nigerian pumpkins. _____________________________________________________________________________________________________________ Keywords: genotypic coefficient of variation (GCV), heritability (broad sense), path-coefficient, phenotypic coefficient of variation (PCV)
Genetic Divergence in Pumpkin (Cucurbita Moschata Duch Ex Poir)
A Field experiment was conducted in Research and Development farm of Lal Teer Seed Ltd. to estimate the genetic divergence among the 21 genotypes of pumpkin were estimated using D2 and principal component analyses. The genotypes under study grouped in to six clusters. The inter-cluster distance was larger than the intra-cluster distance suggesting wider genetic diversity among the genotypes of different groups. The intra-cluster value was maximum in cluster VI and minimum in cluster III. The maximum inter cluster distance average D2 value was observed between cluster I and cluster III (25.75) indicating wide range of genetic diversity between these two clusters. Thus the genetically diverged genotypes could be used as parent in hybridization program for getting desirable segregants. The lowest inter cluster divergence was observed between cluster III and IV (7.14). Cluster I showed the lowest mean values for days to first male and female flowering and highest mean values for flesh thickness, number of seeds per fruit and brix (%), while cluster VI revealed the highest mean vales for fruit diameter, single fruit weight and yield per plant. Germplasms much in use of the above mentioned characters both in cluster I and VI would offer a good scope of improvement of the crop through rational selection for hybrid breeding program.
Journal of Applied Research on Medicinal and Aromatic Plants, 2018
Twenty one accessions of Cucurbita pepo and eleven accessions of Cucurbita moschata were collected from different regions of Iran and variations in fruit and seed characters evaluated during 2016-2017. The basic statistics of traits has demonstrated considerable variability among accessions. Correlation analysis revealed some important associations among studied traits. In C. pepo, a positive correlation were between seed width and fruit weight, seed weight, fruit flesh thickness, fruit cavity diameter and seed length and in C. moschata, total soluble solid (TSS) was positively correlated with fruit flesh thickness, fruit weight and fruit yield and negatively correlated with fruit weight/seed weight. PCA generalized 15 quantitative characters to five PCs in C. pepo and four PCs in C. moschata having Eigen value > 1 explaining 89.85% and 87.13% of the total variability, respectively. Cluster analysis classified C. pepo accessions into six and C. moschata accessions in five divergent groups. The result showed that in C. pepo accessions we can use cluster II members (P02 and P15) as normal seed types and P03 and P05 as naked seed types for next breeding programmes as well as seed production. Among C. moschata accessions we suggest M05 and M11 for next breeding programmes and consumption as pumpkin, also we suggest cluster I (M02 and M03) as the best accessions for consumption their fruits as pumpkin.
Genetic divergence among pumpkin (Cucurbita moschata Duch ex. Poir) landraces of Assam
The Pharma Journal , 2022
Pumpkin (Cucurbita moschata Duch.) is one of the most popular summer vegetable crops and belongs to the Cucurbitaceae family. Thirty diverse pumpkin landraces representing eight districts of Assam comprised the investigation, carried out at the Instruction-cum-Research (ICR) Farm of Assam Agricultural University, Jorhat, during Rabi 2018-2019. Genetic divergence in 30 pumpkin landraces for 27 different traits using Mahalanobis D 2 statistics and Tocher's clustering generated five clusters of the 30 pumpkin landraces. Diversity analysis revealed that the highest genetic diversity was evident between the cluster pairs II-V, I-V, I-V and IV-V, respectively; the landraces from these clusters may be selected as parents in future hybridization programs to obtain superior combinations and heterosis in segregating generation. The single landrace Dibrugarh-1 belonging to cluster IV stood most diverse among 30 landraces and recorded a high cluster mean for yield per plant, which can serve as a suitable parent for the hybridization programme. Landraces Karbi Anglong-1, Haflong-1, Jorhat-1, Majuli-1 and Lakhimpur-1 belonged to the best mean cluster group V; they showed the highest intra-cluster distance, indicating the presence of heterogeneity among the landraces and they can be parents in hybridization programme.
NOVEMBER 2020, 2020
This study evaluated the genetic diversity among 18 inbred lines of Pumpkin (Cucurbita moschata) using HFO-TAG (high frequency oligonucleotide–targeting active gene) markers. The inbred lines were selected from six different populations in Saudi Arabia and Egypt according to genetic distance and population origin. A total of 132 alleles were detected. Sixteen HFO-TAG markers averaged 8.25 alleles per primer with 125 alleles showing polymorphisms that averaged 7.81 alleles per primer. A cluster analysis of the means of the HFO-TAG data created three groups with similarity coefficients between 0.34 and 0.74. In general, the 18 inbred lines were separated according to pedigree and population origin. Hybrids from the chosen inbred lines, S1 L-1 with E L-2, S1 L-2 with E L-3, and S1 L-3 with E L-1, may be the basis for improved hybridization programs and can be used in future hybridization program
Genetic divergence in pumpkin (Cucurbita moschata L.) Genotypes.pdf
Genetic diversity using Mahalanobis's D 2 technique was studied for yield and its components on twenty one genotypes of pumpkin (Cucurbita moschata L.). Quantification of variability for each character was done using the Shannon Weaver Diversity Index. High degree of variation was exhibited within the collection, as reflected by mean diversity index value of 0.80. Data were subjected to principal component analysis (PCA), principal coordinate analysis (PCO), canonical variate analysis (CVA) and non-hierarchical clustering to identify suitable parents having distant relationship for hybridization program. The genotypes were grouped into five different clusters. Cluster IV contained the maximum number of seven genotypes whereas cluster I contained least number having only one genotype. The lowest inter-genotypic distance (0.75) was found between BD-2174 and BD-9489 where the highest (47.46) was between BARI Mistikumra-1 and BD-2150. The maximum inter cluster distance was observed between cluster II and III (17.922) and the minimum inter cluster distance was observed between cluster II and IV (6.825). The maximum intra cluster distance was noticed for the cluster V (0.261) and the minimum intra cluster distance was found in cluster I (0.00). Cluster I contained the highest mean values for pedicel length of male flower, number of male flowers/plant, fruit length, fruit breadth, single fruit weight and fruits/plant. Cluster II contained the highest mean values for days to first male and female flowering. Cluster III contained the highest mean values for leaf breadth, pedicel length of female flower and number of female flowers/plant. Leaf breadth, pedicel length of male flower, number of male flowers/plant and fruits/plant were the important components of genetic divergence in the studied materials. Based on inter cluster distance, inter genotypic distance and consideration of desirable characters for high yield potential, the genotypes G19 (BARI mistikumra-1) and G20 (BARI mistikumra-2) from cluster II; G21 (BD-2150) from cluster I and G1 (BD-2151) and G13 (BD-266) from cluster III can be selected as better parents for future hybridization program.
This study was carried out to determine the efficacy of inter simple sequence repeats (ISSR) and sequence-related amplified polymorphism (SRAP) techniques for molecular characterization some Cucurbita genotypes including naked (hull-less) seed pumpkin. Plant material consisted of sixteen genotypes belonging to Cucurbita pepo L., and four genotypes belonging to Cucurbita moschata Duchesne, and four genotypes belonging to Cucurbita maxima Duchesne. A larger part of the Cucurbita pepo genotypes (7 Turkish and 4 foreign) were seed pumpkin and some of them were naked seed types used as appetizer and/or for oil production. Morphological characterization was also done according to UPOV criteria. The sixty bands were obtained by using 8 ISSR primers and all these bands were found polymorphic. In the SRAP study, 8 primer combinations were used, a total of 71 bands were scored and all these bands were polymorphic. In the ISSR analyses, the genetic similarity coefficients varied between 0.07 and 0.96, while in SRAP it was between 0.13 – 1.0. The correlation coefficient between ISSR and SRAP genetic similarity data was very high (r = 0.947). The genetic variation as measured by ISSR and SRAP markers revealed high diversity among Cucurbita genotypes (H = 0.30, I = 0.46 and 100 % polym.). The genetic diversity among Turkish naked seed pumpkin genotypes (H = 0.09, I = 0.14 and 26.7 % polym.) was only a little less than that of the foreign accessions (H = 0.12, I = 0.18 and 32.1 % polym.). Some differences were observed between molecular and morphological studies, and it was concluded that only morphological or molecular analyses but a combination of both approaches are often more reliable in genetic variability studies in Cucurbita genus.
Biological forum, 2023
Genetic variability and its proper characterization are of vital importance in hybridisation programme of a crop for making a successful rapid improvement. In India, there is a wide range of genetic variability in pumpkin but, not much attention has been given to its improvement programme. Moreover, pumpkins (Cucurbita spp.) are grown as a summer crop in Terai region of West Bengal and no suitable genotypes are available for winter season cultivation. Hence, the present study focuses on identifying and conserving the superior genotypes for off-season to facilitate the future breeding programme. The present experiment was carried out at the experimental field of the department, Vegetable and Spice Crops,