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Volume 6 Number 2 2012
CONTENTS AND ABSTRACTS
Sunita Singh, Srinivasulu K. Reddy, Narendra Jawali (India) Genetic Diversity Analyses of Mungbean (Vigna radiata [L].Wilczek) by ISSR (pp 73-83)
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Original Research Paper: In the present study 3′ anchored ISSR primers were designed, and after optimizing each primer annealing temperature for obtaining a higher number of markers per primer, they were used to analyze genetic diversity among 87 mungbean genotypes from India and neighboring countries. Following screening the 24 ISSR primers, 8 primers that yielded a clear banding pattern were chosen. Out of a total of 145 bands, 135 were polymorphic. An average of 18.12 bands and 16.87 polymorphic bands per primer was obtained. A dendrogram revealed clustering of genotypes into 5 clusters. The first two clusters individually included the genotypes developed at two of the agricultural research institutes in India. Cluster three included genotypes developed in and around India, and cluster 4 included the genotypes that were local collections of mungbean from India and the fifth cluster included exotic and old selections of mungbean. Analyses showed that both resolving power of primer and number of polymorphic bands showed a positive correlation with the number of genotypes identified.
Mukesh Singh, Rajat Kanti Chawdhari, Ila Chawdhari (India) Assessment of Genetic Diversity among Elite Cultivars of Ricinus communis L. Using RAPD Markers for Plant Breeding (pp 84-88)
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Original Research Paper: The present investigation screened the diversity among 19 elite cultivars of castor bean (Ricinus communis L.) genotypes based on RAPD markers together with morphological traits in an approach to mine genes governing commercially important traits for future crop improvement programmes. A total of six primers were selected from an initial screening of 64 RAPD primers. The frequency of polymorphic amplicons observed among cultivars varied greatly from 0.05 to 0.95 in all 19 cultivars. A dendrogram showing genetic similarities among the cultivars was constructed based on the polymorphic bands using UPGMA cluster analysis. The UPGMA clustering method revealed two major groups. The first one was made up of two cultivars, ‘DCH 190’ and ‘RG 90’ while the remaining cultivars were clustered into the second group. Cultivars belonging to the second group were grouped into five sub-clusters. Genetic differences ranging from 0 to 0.86 among the cultivars indicate a diverse gene pool in the castor bean genotypes studied. Morphological and RAPD tools to determine genetic diversity among R. communis cultivars were established.
Mejda Cherif, Dhekra Chaouachi, Wissal Fériani, Salah Rezgui (Tunisia) Resistance of Wild Barley (Hordeum spontaneum, H. marinum and H. murinum) to Pyrenophora teres and Rhynchosporium secalis causing Net Blotch and Scald Diseases in Tunisia (pp 89-94)
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Original Research Paper: Resistance to net blotch and scald in the seedling and in the adult growth stages were evaluated in 56 accessions of wild barley (Hordeum spontaneum, H. marinum and H. murinum) andseven varieties of H. vulgare. Generally, the screened barley genotypes were more resistant than the four checks for net blotch and scald diseases. Results of net blotch evaluation indicated that 88 and 51% of the barley genotypes were significantly more resistant than the most resistant check in the seedling and the adult growth stages, respectively. The H. marinum genotypes collected from Algeria and Egypt (accessions 4, 5 and 7) and the H. spontaneum genotypes collected from Afghanistan, Iraq and Syria (accessions 14, 25 and 43) were the most resistant in both growing stages. For both diseases (net blotch + scald), 36% of the evaluated barley genotypes were significantly more resistant than the most resistant check to a mixture of isolates. According to their reaction to both diseases, the accessions of H. murinum from Armenia, of H. marinum from Algeria, Egypt and Kazakhstan, and of H. spontaneum from Afghanistan, Azerbaijan, China, Egypt, Iraq, Lebanon, Libya, Syria, Turkmenistan, Turkey and Uzbekistan showed the highest level of resistance in the field. For scald, 45 and 15% of the evaluated barley genotypes exhibited more resistance than the mid check at seedling and adult growth stages, respectively. Among the evaluated barley genotypes, three accessions of H. marinum collected from Algeria and Egypt (accessions 4, 5 and 7) and two accessions of H. spontaneum collected from Afghanistan and Egypt (accessions 14 and 22) were resistant in both stages.
Wissal Fériani, Mejda Cherif, Salah Rezgui (Tunisia) Preliminary Genetic Analysis of Resistance to Scaldin Tunisian Barley (pp 95-99)
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Original Research Paper: Leaf scald (Rhynchosporium secalis) of barley (Hordeum vulgare L.) is a serious disease in many barley-growing areas in Tunisia. A doubled-haploid barley population from a cross between the two-rowed cultivar ‘Roho’ and the six-rowed line ‘90’ was evaluated for its resistance at the seedling stage to three isolates (Bousalem2, Krib5 and Teboursouk4) of R. secalis. The obtained frequency distributions suggest that resistance to Bousalem2 and Teboursouk4 isolates were polygenic whereas resistance to Krib5 isolate seems to be governed by two complementary genes. Heritability of the resistance to all isolates was relatively high (64%), although the genotype × isolate interaction effects were significant. Analysis of variance indicated that scald resistance was not dependent on row type. Three QTLs localised on chromosomes 3H, 4H and 6H were identified by the individual marker analysis with the Marker × Isolate interaction model.
Ramzi Chaabane, Sahari Khoufi, Khalil Khamassi (Tunisia), Jaime A. Teixeira da Silva (Japan), Emeni Ben Naceur, Houcine Bchini, Elyes Babay, Houda Ouji, M’barek Ben Naceur (Tunisia) Molecular and Agro-physiological Approaches for Parental Selection before Intercrossing in Salt Tolerance Breeding Programs of Durum Wheat (pp 100-105)
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Original Research Paper: A set of six Tunisian durum wheat varieties (Triticum turgidum L. subsp. durum Desf.) were used for developing and validating an approach to select parental genotypes before intercrossing them for salt tolerance breeding programs. This research was designed to study both molecular genetic diversity and differences in patterns of agro-physiological responses to salt stress. Different agro-physiological measurements were conducted for both the saline treatment (10 g/l NaCl) and the control. The data were converted to salt tolerance indices to allow comparisons among genotypes for salt sensibility. Genetic diversity among these varieties was determined by comparing their molecular traits. A dendrogram of genetic similarity was established using 46 polymorphic markers from eight SSRs and four RAPD primers. The results revealed that the most affected agro-physiological parameters were tiller number, chlorophyll content at 110 and 120 days, shoot dry weight, number of spikes/plant and total grain yield. For these parameters the most affected genotypes were ‘Karim’ and ‘Nasr’ and the least affected were ‘Maali’ and ‘Razzek’. The dendrogram discriminated ‘Karim’ from the remaining analysed varieties. Except for ‘Karim’, the remaining varieties were tightly clustered in the dendrogram, which reflects a narrow genetic base and low genetic variability among those genotypes. The genetic diversity of Tunisian durum wheat varieties could be enlarged by combining desired traits from different local and wild populations of different geographical origins into the breeding lines. Finally, we conclude that both molecular and agro-physiological approaches are helpful for current and future breeding programs in order to select genetically distinct parents with different salt tolerance components.
Ezatollah Farshadfar, Valiollah Rasoli, Reza Mohammadi, Zahra Veisi (Iran) Path Analysis of Phenotypic Stability and Drought Tolerance in Bread Wheat (Triticum aestivum L.) (pp 106-112)
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Original Research Paper: In order to determine stable and drought-tolerant bread wheat genotypes and relative contribution of yield components in the genotype-environment (GE) interaction, field experiments were conducted with 14 genotypes for 3 consecutive years (2008-2011) under rainfed and irrigated conditions. Descriptive diagrams and combined analysis of variance indicated highly significant differences for GE interaction and high variability for yield and yield components indicating the possibility of selection for stable and drought-tolerant entries. AMMI-stability value (ASV) and yield stability index (YSI) discriminated genotype 10 as the most stable genotype with high grain yield (534.5 g). Path analysis revealed that the relative contribution of a genotypic component 1000-seed weight (TSW) in the phenotypic stability of grain yield was higher than that of number of spike per plant (SPP) and number of seed per spike (SPS). Environmental components of GE interaction exhibited that absolute value of r1 (first environmental component) in all environments was higher than the second (r2) and third (r3) environmental components. In addition, variation of r1 was more than r2 and r3, and that of r2 was higher than r3 indicating that sensitivity of number of spike per m2 (NS) and SPS to the environmental variation was higher than TSW. Therefore high grain yield and stability of genotype 10 was because of higher genotypic component V3 (TSW) and lower environmental components r3 (TSW). Path coefficient and cluster analysis of drought susceptibility index (DSI) discriminated genotypes Croos alborz, Ww33G.Vee"S".Mrn.3.Atilla.Tjn, Aazar-2, Sardari, Azd.HD2172..Kayson.Glenson.3.170-28.Ning8201, Ww33G.Vee"S".Mrn.3.Atilla.Tjn and T.AEST..SPRW"S"..CA8055.3.BACANORA88ICW92-0477 as drought tolerant with high grain yield for rainfed condition, while genotypes Shi#4414.Crow"S"..Fow-1 and CHAM-8.MAYON"S'.CW93-0031-1AP-OL-OBR-2AP-1AP-OAP as drought sensitive and desirable for irrigated condition.
Ezatollah Farshadfar, Reza Mohammadi, Zahra Vaisi (Iran) Screening and Repeatability of Quantitative Indicators of Drought Tolerance in Wheat-Barley Disomic Addition Lines (pp 113-120)
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Original Research Paper: To locate the genes controlling drought tolerance in barley (Hordeum vulgare cv. ‘Betzes’), a set of complete wheat-barley disomic addition lines (DALs) along with two donor (barley) and recipient (wheat) parents were evaluated under drought stress and non-stress conditions for three cropping seasons. Several drought tolerance indices based on the grain yield of DALs in the stress and non-stress conditions were used to study the genetic variation in barley and to investigate relationship between the indices within and over the years. Differences in ranking of genotypes based on each index were observed from year to year, indicating that the drought tolerance of genotypes is influenced by year effect. The relationships among the indices and their association with mean yield based on Spearman’s rank correlation were determined in each of the three cropping seasons. Principal component analysis (PCA) based on the Spearman’s rank correlation matrix revealed that the screening methods were significantly inter-correlated with each other indicating that several of the statistics probably measure similar aspects of drought tolerance. The stress tolerance index (STI), geometric mean productivity (GMP), harmonic mean (HM) and mean productivity (MP) were consistently and highly correlated with each other over there cropping seasons, and, therefore, could be used to select drought tolerant genotypes with high yield performance in both stress and non-stress conditions. The stress susceptibility index (SSI), yield stability index (YSI), tolerance (TOL) and sensitivity drought index (SDI) showed consistent relationships with each other over years and can be used to screen the drought resistant and stable genotypes. According to multiple year data, most of the genes controlling drought tolerance are located on chromosome 7H in barley.
Ezatollah Farshadfar, Hojjat Hasheminasab (Iran) Investigating the Combining Ability and Genetic Constitution of Physiological Indicators of Drought Tolerance in Bread Wheat (Triticum aestivum L.) Using GGE Biplot Methods (pp 121-128)
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Original Research Paper: To study the combining ability and genetic constitution of physiological indicators of drought tolerance in bread wheat using GGE biplot techniques, an eight-parental diallel cross, excluding reciprocals, was grown in a randomized complete block design with three replications under two different water regimes (irrigated and rainfed) in the Agricultural Research Institute of Sararood, Kermanshah, Iran. Significant differences were found for yield potential (Yp), stress yield (Ys), relative water content (RWC) and leaf water potential (LWP). The result of biplot analysis showed that the Parent A, F, B, F and E were The best general combiners with positive effects, for improvement of Y, RWC, LWP, RWL and chlorophyll fluorescence (CHF) under drought conditions respectively, also parent C exhibited positive GCA for all traits. The crosses (A, C and H) × (B, F and G), (F and D) × (A, C and G), (F and E) × (A, H, C and D), (F, B and E) × (C, G and H) and (F and E) × (A and H) for Y, RWC, LWP, RWL and CHF were heterotic groups with different dominant tolerance genes (D1 and D2), respectively. The polygon view of the biplot indicated combining A × G and F × E produced the best drought tolerance hybrids for all the traits through integrated the four tolerance genes (A1, A2, D1, and D2). G was the best tester in all, as it was very close to the ideal tester. The results showed additive gene effects mainly that control the physiological indicators of drought tolerance. Thus, genetic gain in developing tolerance in bread wheat can be achieved through selection.
Bhabendra K. Biswas, Nazmul Alam (Bangladesh), Jaime A. Teixeira da Silva (Japan), Mohammad M. Haque, Mohammad A. K. Azad, Mohammed K. Hossain (Bangladesh) Existing Status and Genetic Divergence of Agro-Morphological Characters in Bangladeshi Fine Rice (pp 129-134)
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Original Research Paper: A set of 30 rice (Oryza sativa L.) cultivars including 28 primitives, one exotic and one improved variety were collected from different agro-ecological zones of Bangladesh. The experiment was conducted in a randomized complete block design with three replications during the wet season (July-December) of 2009 at the Plant Breeding Field Laboratory, Hajee Mohammad Danesh Science and Technology University, Dinajpur. The existing status regarding cultivation and preservation attitude were realized through an oral interview with 20 randomly selected farmers of each location from where a particular cultivar was collected. Four cultivars (‘Kalozira’, ‘Badshabhog’, ‘Zethakatari’, ‘Katari’) were most preferred by innovative farmers due to their use as food and in different traditional and religious festivals. Cultivars such as ‘Shilkamal’, ‘Binnipakri’, ‘Darkashail’, ‘Dudshar’, ‘Lalchikon’ and ‘Uknimodhu’ were rarely cultivated, hence the need to preserve them. The 30 cultivars were grouped into 7 clusters through principal component analysis and D2 statistics based on 12 agro-morphological characters. Cluster VI comprising ‘BR34’ and ‘Darkashail’ produced the highest yield (4.05 t/ha). Days to maturity was generally high in all 7 clusters and ranged from 112.7-132.3 days; no cultivars matured slowly. Therefore, the development of rapidly maturing varieties by conventional breeding is assumed to be very difficult in fine rice. Among the 12 characters, spikelets/panicle exerted maximum weighting (20.37%) on total genetic divergence while percentage sterility had the least weighting (3.58%). Since highest intercluster distance (651.88) was observed between clusters III (‘Malshira’, ‘Chiconsarna’, ‘Lalchicon’, ‘Radhunipagal’, ‘Nazirshail’, ‘Lalfota’, ‘Sumonsarna’) and VI (‘BR34’, ‘Darkashail’), parents could be selected from these two clusters to obtain desirable segregants in the F2 generation. Alternatively, one parent from each cluster could be selected to initiate a diallel cross to assess the best cross combination and to identify those parents with high general combining ability for improvement.
Md. Moniruzzaman, Md. Mahmudul Hasan (Bangladesh), Jaime A. Teixeira da Silva (Japan), Md. Jashim Uddin, Md. Mainul Hasan, Monjila Begum, Md. Abu Syed (Bangladesh) Variability Study in Inter-varietal Crosses of Aubergine (Solanum melongena L.) (pp 135-138)
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Original Research Paper: A field experiment was carried out to assess the genetic variability of yield-attributing traits in 12 aubergine genotypes. The evaluated parameters were number of primary and secondary branches/plant, days to flowering, number of fruits/plant and fruit length, all of which differed significantly in different genotypes. Small differences in genotypic and phenotypic variance and coefficient of variation, high heritability as well as high genetic advance were observed for all traits, indicating additive gene effects. Line-23×Line-24F2 performed best in terms of number of primary branches/plant (8.5), early flowering (48.18 days after transplanting), and maximum number of fruits/plant (37.29). Line-27 required more days to flowering (58.16) while BARI-2 produced most secondary branches/plant (20.59) and longest fruit (13.70 cm). Hence, a cross between Line-23×Line-24F2 and BARI-2 is suggested for increased value-added traits.
Solomon Ukaan, Peter Ogbonna (Nigeria) Genetic Variability and Character Association in Sesame (Sesamum indicum L.) Accessions (pp 139-143)
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Original Research Paper: This study was conducted to determine the genetic variability and character association in 13 sesame (Sesamum indicum) accessions. The accessions were evaluated in replicated field experiments at the Department of Crop Science Teaching and Research Field, University of Nigeria, Nsukka under two planting seasons. The result showed significant differences among the accessions in most of the traits studied. The genotypic and heritability estimates were high for all the growth and yield attributes, indicating that these traits have high transmitting ability to subsequent generations. The highest genetic and phenotypic variance were observed in number of seeds/plant (5389.3 and 5391.3) in 2009 with number of capsules/plant (223.64 and 226.03) in 2010. However, for genetic and phenotypic coefficients of variation, the highest were observed in seed yield/ha and seed yield/plant (37.80 and 40.01) in 2009 while seed yield/plant (40.54 and 40.56) gave the highest in 2010. Apart from number of days to emergence in 2009 planting season, high heritability values were obtained on all the traits during the two planting seasons indicating that selection for those traits would be very efficient. The correlation matrix showed that seed yield/plant correlated positively and significantly with number of leaves, plant height, number of branches, stem girth, number of flowers/plant, number of capsules/plant, number of seeds/capsules, capsule length, capsule weight/plant, 1000-seed weight and number of seeds/plant. This indicates that increase in these traits will ultimately increase seed yield.
Mohammad A. K. Azad (Bangladesh), Jaime A. Teixeira da Silva (Japan), Bhabendra K. Biswas (Bangladesh) Genetic Correlation among Various Quantitative Characters in Maize (Zea mays L.) Inbred Lines (pp 144-146)
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Short Communication: Thirty maize (Zea mays L.) inbred lines were grown in a randomized complete block design with three replications to assess the genetic correlation among 13 quantitative traits. A positive correlation with grain yield/plant was recorded for plant height (r = 0.41), ear length (r = 0.54), ear diameter (r = 0.74), number of grains/row (r = 0.47), number of grains/ear (r = 0.45) and 1000-grain weight (r = 0.41). Days to 50% tasselling and days to 50% silking were negatively correlated with yield/plant while days to 50% maturity, ear height, number of ears/plant and number of kernel rows/ear were positively but insignificantly correlated with yield/plant. Ear diameter was the character that most contributed to high yield/plant (r = 0.74) followed by ear length (r = 0.54). A strong positive correlation was observed for grain yield/plant with plant height (r = 0.41), ear length (r = 0.54), ear diameter (r = 0.74), number of grains/row (r = 0.47), and number of grains/ear (r = 0.45) indicating that selection for these characters could help improve grain yield in maize inbred lines.
Ravi V. Mural, Ravindra Sasalawad, Shailaja Hittalmani (India) Evaluation of Rice (Oryza sativa L.) Accessions for Growth and Yield Attributes in Aerobic Condition (pp 147-149)
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Short Communication: The objective of this study was to evaluate 300 rice accessions and four check varieties for growth and yield component traits under aerobic condition. The analysis of variance for the ten characters studies revealed high significant difference among the genotypes both at five and one per cent level of significance except for test weight, seed length and single panicle weight thus, wide range of variability was observed for all the characters. In general, the phenotypic co-efficient of variation (PCV) was greater than genotypic coefficient of variation (GCV) for all the traits studied, indicating significant influence of environment on expression of the traits. The estimate of broad sense heritability (h2) was highest for biomass, genetic advance as per cent mean was high for total seed weight, single panicle weight and number of tiller per plant. High values of PCV, GCV, h2 and genetic advance as per cent mean were observed for grain yield per plant. Total seed weight was positively associated with above ground biomass, single panicle weight and number of tillers. A significant negative correlation between plant heights at 45 DAS with number of tillers was observed. The genotypes viz., MAS-IL858, MAS-IL869, MAS-IL748, MAS-IL835 and MAS-IL707 were found high yielders among introgression lines as compared with checks. |
