000			02533nam a22001817a 4500
100			_aMercy, M.A.
245			_aPerformance of wild Amazonian accessions and hybrid Hevea clones of Wickham origin in a drought stressed environment
260			_bRubber Science, 36(2): 2023. 199-208
520			_aNatural rubber cultivation in India faces adverse effects of drought and cold stresses in the non-traditional rubber growing areas. As genetically divergent germplasm accessions are an excellent repository of various stress tolerance traits, their systematic screening can help to identify potential accessions with intrinsic tolerance to abiotic stresses such as drought, temperature extremes etc. With this objective, a field evaluation of 33 Hevea clones comprising of wild Amazonian accessions and Wickham clones was initiated at Regional Research Stations (RRS), Dapchari located in Maharashtra, experiencing high temperature, high light intensity and very low soil moisture during the summer months. The check clones in the experiment were RRII 105, RRII 430, RRII 414, RRII 208, RRIM 600 and Tjir 1. Growth parameters such as annual girth and girth increment were recorded from the third year onwards. Based on empirical visual scoring of leaf yellowing and drying during summer period, potential drought tolerant clones were identified and they were further evaluated for in vivo leaf chlorophyll stability during the following summer. Based on per cent reduction in chlorophyll content the accessions were ranked for intrinsic tolerance. Among the 20 tested, five tolerant and three susceptible accessions were again evaluated in polybags under controlled moisture stress condition and various drought related physiological parameters were monitored. A structural parameter viz. quantification of intra xylary phloem (IXP) from one-year-old twig samples was also evaluated for its usefulness to identify the potential accessions. These physiological and structural parameters were utilized to compare the actual field performance of these clones. Results indicated significant clonal differences to compare the actual field performance of these clones. Results indicated significant clonal differences leading to the selection of potential candidates towards the development of drought tolerant rubber clones.
650			_aDrought tolerance
650			_aWickham clones
650			_aWild germplasm
700			_aNair, D.B.
700			_aMeenakumari, T
700			_aSingh, M.
700			_aMydin, K.K.
942			_cJS
999			_c75207 _d75207