Mechanism of tolerance and susceptibility of two jute species to water deficit stress
1991
Choudhuri, M.A.
Water deficit stress (WDS), imposed either by holding water for 2 days or by polyethylene glycol (PEG-6000) at 1.0 MP a for 2 h, decreased the relative water content (RWC) and leaf water potential (LWP) in the two Jute species (45 d old), Corchorus capsularis L. (cv. JRC 212) and C. olitorius L. (cv. JRO 632), but more markedly so in the latter. The former species was found to be more tolerant to WDS because of a number of physiological and biochemical factors. C. capsularis has a better capacity for water uptake, water retention and lesser transpiration rate under WDS. This was well correlated with its capacity for more rapid stomatal closure with quicker efflux of K+ from the guard cells compared with C. olitorius subjected to identical WDS. The capacity for quicker proline accumulation in C. capsularis under WDS and its faster decline after stress relief endows it with a better ability for drought tolerance than C. olitorius. The combination of pretreatment of seeds with CaCl(2) followed by foliar spraying of seedlings with ABA acted independently, improving water status of stressed plants. Whilst Ca(++) treatment improved water uptake without having any effect whatsoever on stomatal movement, ABA reduced water loss by inducing stomatal closure without having any effect on water uptake. The above treatments gave better results with C. olitorius suggesting its greater susceptibility to WDS than C. capsularis at comparable external WDS.
显示更多 [+] 显示较少 [-]