STUDIES ON PHYSIOLOGICAL AND BIOCHEMICAL CHARACTERS RELATED TO DROUGHT RESISTANCE IN SUGARCANE (Saccharum officinarum.L)
KrishiKosh
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Title |
STUDIES ON PHYSIOLOGICAL AND BIOCHEMICAL CHARACTERS RELATED TO DROUGHT RESISTANCE IN SUGARCANE (Saccharum officinarum.L)
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Creator |
VIJAY KUMAR, MEDE
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Contributor |
SIVASANKAR, A
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Subject |
irrigation, planting, sugarcane, yields, weather hazards, biological development, vegetative propagation, crops, genotypes, diseases
Saccharum officinarum.L |
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Description |
Field experiments were conducted at Agricultural Research Station, Basantapur, Medak District during 2008-2009 and 2009- 2010 to study the influence of water stress during formative phase (60 to 150 days) in on various morpho-physiological, biochemical, cane yield, sugar and sucrose content in ten sugarcane genotypes. The experiments were laid out in strip plot design with 20 treatments and three replications. The morphological parameters, viz., shoot population, plant height, length and girth of internodes were significantly reduced with imposed moisture stress in all genotypes compared to control ( normal irrigation ). Significant reduction was observed in physiological characters pertaining to leaf viz., growth in terms of leaf unfurling, number of leaves, leaf area during both years in all genotypes in the moisture stress treatment. Among various growth parameters, canopy structure in terms of LAI was found to be significantly influenced by treatments wherein moisture stress resulted in lowering of LAI values significantly during both years. Among genotypes tested 97 R 401 and 98 R 278 exhibited greater reductions in LAI as well as dry matter production during stress and recorded more vegetative growth at harvest, indicative of poor efficiency of partitioning. Photosynthesis related traits such as SCMR , photosynthetic rate ( Pn ), stomatal conductance (gs) and transpiration rates ( E ), Photochemical efficiency ( Fv/Fm ratio ) were significantly affected by moisture stress treatment. Genotypes differed significantly. Among genotypes tested Co 86032 , Co 99004 and Co 94012 exhibited significantly less reduction with respect to all the above parameters with moisture stress imposed during formative phase. Significant positive relationship was observed between Pn and gs, Pn and E as well as E and gs. Calculated values of intrinsic WUE ( Pn/gs ) and extrinsic WUE ( Pn/E ) varied among genotypes tested wherein the limited moisture availability exerted a strong influence on the latter which decreased with water stress compared to control. Among genotypes Co 86032 and Co 99004 exhibited less reduction in extrinsic WUE ( Pn/E ) values under imposed water stress conditions compared to control. Carbon isotope discrimination (CID) is a potential surrogate trait for measuring water use efficiency of a genotype and is generally expressed in parts per mil (‰). Strong negative relation between CID and WUE was established under moisture stress conditions could be used to identify genotypes with high WUE. CID studied in the present study was also significantly influenced by moisture, varieties and their interaction. Among the main treatments, irrigated treatment showed significantly lower CID values compared to moisture stress which has further established that due to moisture stress WUE was significantly affected in sugarcane clones. The varieties Co 86032, Co 99004 and 85R 186 recorded significantly lower CID values both under irrigated and moisture stress conditions. Hence these clones are considered to be high WUE types compared to all other clones, which maintained with low CID values specially under moisture stress conditions. They suggest that variation in photosynthetic capacity/unit leaf area could be largely responsible for genotypic variation in CID. Among various biochemical parameters, contents of proline, nitrogen , sucrose in canes were found to be significantly affected by moisture stress and varied with genotypes in both years. The values were consistently lower with moisture stress in all genotypes where such reductions were of lesser magnitude in Co 99004 and Co 86032 compared to susceptible genotypes. In contrast, the genotypes viz., 97 R 401 , 97 R 278 and Co 94008 exhibited more reductions during experimental studies. There are many below ground constraints on crop growth specially under moisture stress conditions in commercial sugarcane production. An important function of plant root system is to absorb water from the soil and transport to the shoot. Hence, the efficiency of soil water uptake by root system is key factor in determining the balance between translocation and shoot water status. The root volume, root spread and distribution, root length and shoot root ratio are prime factors concerned under moisture stress to extract material for its growth. Deeper rooting reduces the vulnerability of crops to the soil water deficit by providing increased capacity for uptake of deeper zones, drought tolerant cultivars have a tendency to develop deep root system as like the variety 85 R 186 . Yield in sugarcane is reported to be as sensitive soil water stress, resulted in decreased cane yield. The water stress reduces cane yield more in the susceptible genotypes, but the reduction in yield due to water stress was greater in 97 R 401. The high yielding genotypes undergo greater per cent reduction in cane yield when stressed. The low potential genotypes were the most tolerant to water stress, because their yield reduction from non stress to stress was minimal. The yield reduction was carried from formative stage of crop growth mainly affecting the yield attributes., viz. height, girth and weight were decreased due to stress and the decrease was less in a resistant variety,. More reduction in stalk girth due to stress affecting the cell elongation characteristics in the sensitive genotype. Under moisture stress condition the highest yield was recorded for Co 86032 and Co 99004. Thus, the observed growth of sugarcane was associated with better root growth supporting canopy development and photosynthesis under moisture stress while better photosynthetic performance was observed to be dependent on traits such as SCMR, Photochemicial efficiency, WUE. Further, biochemical traits such as proline , nitrogen and sucrose contents have a strong association with cane and sugar yield in sugarcane genotypes. Based on all the parameters, it can be concluded that sugarcane genotypes viz., Co 99004 , Co 86032 and Co 94012 could be categorized as “ drought tolerant ” while the genotypes 97 R 401, 98 R 278 and Co 94008 could be referred to as “drought susceptible”. |
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Date |
2016-06-09T10:35:49Z
2016-06-09T10:35:49Z 2012 |
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Type |
Thesis
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Identifier |
http://krishikosh.egranth.ac.in/handle/1/67069
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Language |
en
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Relation |
D9095;
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Format |
application/pdf
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Publisher |
ACHARYA N.G.RANGA AGRICULTURAL UNIVERISTY
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