TITLE:
Selection of Rice (Oryza sativa L.) Cultivars Tolerant to Drought Stress at the Vegetative Stage under Field Conditions
AUTHORS:
Sumontip Bunnag, Prapaporn Pongthai
KEYWORDS:
Proline; Leaf Rolling; Leaf Death; Leaf Water Potential
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.4 No.9,
August
21,
2013
ABSTRACT: Water status
is one of the critical factors affecting rice production. Rice cultivars
tolerant to drought stress at the vegetative stage under field
conditions were selected. Seven rice cultivars, namely, KDML 105, IR58821,
CT9993, IR62266, IR57514, IR52561 and BT, were included in this study. The
plant height, number of tillers per plant, leaf rolling, leaf death, leaf water
potential, relative leaf water content and proline content in plants subjected
to drought stress for 0, 20 and 60 days were recorded. Based upon the levels of
water stress tolerance, three groups of rice cultivars were recognized, as
follows: highly drought-tolerant, moderately drought-tolerant and
drought-sensitive cultivars. The CT9993 rice cultivar was considered to be a
highly drought-tolerant cultivar. The moderately drought-tolerant cultivars
included KDML 105, IR58821, IR57514, IR52561 and BT. The IR62266 cultivar was
considered sensitive to drought.