Salinity is the most significant constraint to wheat cultivation in the salinity-affected areas. Saline-prone soils can be brought under cultivation by the development of salt-tolerant lines through molecular breeding aided by diversity analysis and molecular screening. The study aimed to screen for salinity tolerance and elucidate the extent of diversity among 75 wheat varieties and accessions. This molecular analysis and detection used 21 linked SSR markers. The study identified 202 alleles in 75 genotypes of wheat, giving 9.6 alleles on an average for salt tolerance screening. The mean polymorphism information content (PIC) of 0.7599 and the Nei’s (1973) gene diversity of 0.7856 were recorded. The accessions possess higher gene diversity and PIC than the cultivars. The average genetic similarity matrix coefficient was 0.60 within the range of 0.19 and 1.00. Similarity indices based UPGMA cluster analysis separated the 75 germplasm into six clusters. Eight genotypes grouped in sub-cluster Ib together with the positive control BINA Gom-1. Therefore, these eight genotypes were identified as potential salt-tolerant by molecular analysis using SSR markers linked to salinity. The gene diversity estimated, and the germplasm identified as potential salt-tolerant are promising for use in wheat breeding to incorporate salt tolerance in novel cultivars by marker-assisted breeding.
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Flooding often occurs during the vegetative stage in freshwater swamps and rainfed lowlands, and therefore submergence tolerant rice varieties are needed. This study was aimed at evaluating rice lines to submergence stress. The experiments were conducted at Indonesian Center for Rice Research (ICRR) experimental station in Sukamandi, Subang, West Java, each in different environmental conditions: (1) submergence condition, which was conducted in a submergence pool and (2) optimal condition, which was conducted in the irrigation field. Ninety-five lines and four check varieties, namely Inpari 30 Ciherang Sub1, IR42, Limboto, and IR20 were used. An augmented design with five blocks was followed in each environment. Three selection methods were used: (1) selection based on survival rate and vigor, (2) selection based on productivity under submergence and sensitivity index on productivity character, (3) selection based on the weighted selection index using sensitivity index variables of morphological and agronomic characters. The clustergram analysis with heatmaps method was used to compile of three previous selection methods to facilitate scientist in clarifying tolerant and sensitive lines. There were eighteen lines selected as tolerant to submergence stress, i.e., line no. 9, 15, 34, 46, 47, 48, 49, 50, 53, 55, 56, 57, 59, 60, 61, 62, 89, and 90. These lines are considered promising for breeding improved rice varieties tolerant to submergence.
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Drought is one of the major abiotic factors that have a serious effect on the production of cereals crops including maize, which is grown widely in the world. Screening based on drought facilitates selection of inbred lines and an understanding of drought-tolerant traits. The effect of drought stress and rescue after stress on maize inbred lines was investigated in this study. Different plant growth attributes namely plant height, leaf area and weight, stem weight, root length, shoot and root fresh and dry weight, and total leaf chlorophyll content were measured. Six flint inbred lines (FLD 12, FLD 23, FLD 24, FLD 33, FLD 35, and FLD 37) were screened as drought-tolerant lines, whereas another six flint inbred lines (FLD 01, FLD 13, FLD 16, FLD 18, FLD 29, and FLD 31) were screened as drought susceptible lines. Growth attributes under different drought conditions were subjected to a correlation test and analysis of variance and showed highly significant relationships with each other. The drought effect differed with different inbred lines, indicating a wide variability of drought response at the early growth stage of maize plants. The results obtained from this study will be useful for selecting maize inbred lines in future breeding programs for enhancing drought tolerance.
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Low temperature stress at the seedling stage of rice is an important factor causing the leaf discoloration, wilting and consequently leads to non-uniform crop maturation. In order to screen the cold tolerance elite lines efficiently, the five cold treatment conditions with different water and air temperature were designed and treated at seedling stage. For the evaluation of seedling tolerance, the injury was scored by visual rate and measured by Soil and Plant Analyzer Development (SPAD) meter. In the reactions of varieties for each treatment, the treatment ‘B’ condition, 12ºC mean water with 24ºC mean air, shows clear discoloration, so it’s correlation coefficient was highest (r=−0.9,
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