Effect of Simulated Waterlogging Condition Imposed at Early Vegetative Growth on Final Yield in Greengram (Vigna radiata)

Background: ‘Rain’ plays a very important role since most of the agricultural productivity is rainfall dependent. However at the same time unpredictable and untimely rainfall are also responsible for crop loss. In India, our North-eastern region receives the highest amount of rainfall. Even in pre-monsoon season, our region receives very high amount of rainfall which hampers the crop production, especially the summer season greengram. Hence, an effort had been made to screen some genotypes of summer greengram, tolerant to waterlogging condition. A study was carried out during the summer season to evaluate the physiological performance of some greengram genotypes as influenced by waterlogging condition of varying duration imposed at early vegetative stage of growth.Methods: From an initial screening of forty genotypes in laboratory condition, five genotypes were selected based on germination percentage, seedling length and vigour index. These five genotypes were further evaluated in a pot experiment with four treatment combinations comprising of control (T1), waterlogging for 4 days (T2), waterlogging for 8 days (T3) and waterlogging for 12 days (T4). Waterlogging conditions were created in the pots at the time of sowing. Result: Water logging caused adverse effect on growth and development of all the genotypes, with the longest waterlogging showing severe deleterious effect. The parameters viz. germination percentage, leaf chlorophyll content, leaf area, plant height, nitrate reductase activity, number of seeds pod-1, pods plant-1, root length, number of root nodules plant-1 and harvest index were found to decline under waterlogged condition whereas, lipid peroxidase and superoxide dismutase activity showed higher values under waterlogged condition. The performance of the genotype Sadiya Local was found to be the best from the point of view of tolerance as indicated by higher seed yield followed by AKM 12-28. The better performance of this genotype appeared to be related to the higher values for some traits viz. germination percentage, leaf chlorophyll, nitrate reductase activity, superoxide dismutase activity, number of pods plant-1 and harvest index.

Source and mobilization mechanism of arsenic contamination in Manipur, Northeast India

<p>India is one of the fastest economic growing and second-largest country by population. More than 75% people are living in rural areas and engage with agricultural activities for livelihood. A significant portion of the revenue comes from agriculture which cause ignorance in follow the guideline to get more yield. The supply of good quality food and drinking water are the necessity for economic and social health welfare of urban and rural population. In this study, we have observed that the groundwater quality is being degrading due to improper implementation of the rules and regulation. Twenty three groundwater sample were analyze for arsenic and trace elements contamination. The arsenic content in groundwater ranging from 10 to 780 µg/L, which is far above the levels for drinking water standards prescribed by World Health Organization (WHO). For identify the provable source of the contamination, four soil sample were analyzed and observed arsenic content ranging from 110 to 190 mg/kg. Rice is the staple food and ultimately cultivating the paddy crop on more over 80% of the agricultural land. The Paddy crop requires a large amount of water, ultimately maintain the waterlogging condition in the agricultural field. This waterlogging condition is providing a long time to get dissolution of the arsenic bearing minerals present in the soil. This study concluded that the traditional practicing of continuous growing paddy crop in the same field leading to groundwater contamination. The crops cycling could be a better option for reducing the contamination at a local scale.</p>

SALICYLIC ACID INDUCES PHYSIOLOGICAL AND BIOCHEMICAL CHANGES IN PEONY UNDER WATERLOGGING STRESS

In this study, the effects of salicylic acid to antioxidative activity and photosynthetic characteristics in waterlogging stress of two peony cultivars (‘Fengdanbai’ and ‘Mingxing’) were investigated. 4-year-old peony grown in different levels of waterlogging stress and then different concentration prepared SA (0.0, 0.1, 0.5 and 1.0 mmol L–1) sprayed on fresh leaves of peony. The antioxidative enzymes activities include superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT), chlorophyll content, relative conductivity and MDA content were measured in leaves about different waterlogging treatment, the photosynthetic characteristics were also measured using photosynthetic measurement system. The results showed that waterlogging stress decreased the chlorophyll content in all peony cultivars leaves, but with SA treatment can inhibit the decrease of chlorophyll content. Relative conductivity increased as the extension of waterlogging time in two cultivars. SA treatment could effectively inhibit the increase of relative conductivity, and 0.5 mmol L–1 of SA was the most suitable concentration. SOD, POD, CAT activity increased first and then decreased in different waterlogging condition, SA significantly increased the activity of various enzymes. MDA content was increase as the expansion of waterlogging time in two cultivars. SA inhibits the increase of MDA content. Of all concentration of SA, 0.5 mmol L–1 was the best concentration to inhibit the waterlogging stress. For the photosynthetic characteristics, the net assimilation rate (Pn), stomatal conductance (Gs), transpiration rate (Tr) and intercellular CO2 (Ci) were decreased under different waterlogging condition. SA treatment can increase Pn, Gs, Tr and Ci of peony.

Anatomical responses of jute (Corchorus capsularis L. cv. D‐154) to waterlogging

The effect of waterlogging (about 2 cm depth for 14 days) on anatomical structure in jute (Corchorus capsularis L. cv. D-154) plants grown in sand culture experiment was studied. Waterlogging resulted in the development of adventitious root, aerenchyma in the cortex of the stem. It also caused a decrease in vascular area as well as size of the vessels having smaller cavity in the root, stem and leaves. Pith area was found to increase in stem under waterlogging condition. Reduced number and closed stomata were found under waterlogging condition. Dhaka Univ. J. Biol. Sci. 27(2): 213-219, 2018 (July)