IJOEAR : December 2015

Combining ability analysis and nature of gene action for grain yield in Maize hybrids

Abstract In the present investigation combining ability analysis and nature of gene action was studied for twenty lines, four testers and eighty hybrids, which were obtained from Line x tester biparental crossing scheme. The twelve characters were studied for winter maize under this experiment. Parental variance, Line variance, and line x tester variance revealed that there were significant differences in all the characters, whereas only tester variance showed three non-significant characters, namely days to 50% anthesis, days to maturity and cob length. The nature and magnitude of gene action showed that the dominance variance major reason towards hybrid performance for all characters. This means that non-additive action is important for the hybrid performance. The most promising crosses for higher yield per ha were L8 x T1 (27.63), L9 x T4 (23.44), L3 X T3 (23.41), L16 x T2 (23.03), L3 x T3 (22.81), L1 x T3 (22.51), L20 x T2 (19.48), L13 x T4 (19.47), L7 x T1 (18.22) and L17 x T4 (17.58) which have shown high SCA effects for grain yield which high parental GCA effects can be exploited for the development of SCHs because of non-additive gene action.

Keywords Combining ability, GCA, Gene action, Maize and SCA.

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Structural diversity and nutrient recycling potentials of three selected agroforestry homegardens in southern Kerala

Abstract Homegardens in Kerala mimic forest ecosystems on account of the tree components included and are agroforestry systems that integrate different agricultural crops and enterprises as per the needs and interests of the farm family. Analysis of the structural diversity and nutrient recycling potentials of three agroforestry homegardens in southern Kerala revealed multi-tier cropping patterns with cropping intensities ranging from 177.18 to 187.04%. Two of the homegardens included livestock components adding to the nutritional security of the family. Diversity indices were in the order 0.92, 1.53 and 0.86. The quantum of litter fall varied with the tree canopies and species, amounting to 473.6, 425.37 and 345.11 kg adding 7.02, 7.517 and 5.165 kg NPK annually in the three homegardens. Maximum nutrient additions were recorded for nitrogen and potassium and least for phosphorus.

Keywords: agroforestry, diversity, homegarden, litter, nutrient

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Exploration of plant biodiversity for nutrient harvesting

Abstract There are considerable differences among plant species in the amount of nutrients required for biomass production, indicating the differential ability of the species to utilize nutrients for growth. Exploitation of this ability for nutrient absorption is a good option for nutrient management in organic agriculture. Different plant species growing in the wild habitats in the Western Ghats and wastelands of the western coasts were screened for phyto-accumulation capacity with respect to macro and micronutrients. Based on the analysis, phyto-accumulators of each nutrient was identified. Considering the overall nutrient concentration, ten plant species were identified as potential plants which can be utilized for nutrient management in organic farming. Plants like Mirabilis jalapa and Canna indica which are super accumulators and possess underground stems are promising plant species for nutrient harvesting as the above ground portion can be harvested without destroying the plants.

Keywords Canna indica, Mirabilis jalapa, Organic farming, Phyto accumulation, Western ghats.

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The Interaction of Fertilizer Levels and Weeding Frequency on Growth and Yield of Roselle

Abstract The study investigate the interaction of fertilizer level and weeding frequency on growth and yield of roselle in Yola , Adamawa State of Nigeria . It was observed from the results that all the parameters increased with increase in level of nitrogen fertilizer except number of days to first flowering and number of days to 50% flowering. For all the values of the parameters taken, the lowest was with treatment 0Kg/ha (control). This indicates that roselle performance increased with increased level of nitrogen fertilizer up to 150kgN/ha.

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Effects of LED light spectra on active oxygen metabolism and expression of antioxidant isozymes in Houttuynia cordata Thunb. seedlings

AbstractThe effects of various LEDs on active oxygen metabolism and patterns of SOD, POD and CAT isozymes in Houttuynia cordata Thunb. seedlings were investigated. After three weeks of light treatment, the MDA content was higher under blue LED compared with the control (P﹤0.05), while it decreased under white, red and yellow LEDs (P﹤0.05). The content of H2O2 was gradually increased in red, yellow, green and blue LEDs. The production rate of superoxide anion increased under yellow and blue LEDs by contrast with the control (P﹤0.05), and it decreased under white LED (P﹤0.05). LEDs altered the banding patterns of POD enzymes where the more loci of POD isozymes were observed under green and blue LEDs. The increased intensities of Fe-SOD were showed in green and blue LEDs. As for Mn-SOD and CAT enzymes, enhanced intensities appeared in all LED groups compared with the control. Our results indicated that the antioxidant system of Houttuynia cordata seedlings were more sensitive to short light wavelength than the long ones.

KeywordsHouttuynia cordata Thunb, LED, light spectrum, Oxidative stress

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