Variations In Adaptation Of Commelina Communis L.to Drought Stress

Commelina communis L.is a summer annual weed and belong to family commelinaceae.The crop suffers heavily due to high infestation of C.communis.Presently weed control strategies such as pre and post emergence herbicides applications have failed to efficiently control C.communis.Therefore,the herbicidal control of C.communis in crops is a challenging task.For this reason,to better understand the ecology of C.communis and use of alternate control practices are now becoming more important to deal with weeds.Therefore,this study was conducted to study the morphological,physiological and molecular mechanism of C.communis to drought stress.Different drought stress treatments were applied to validate the response of C.communis biotypes to drought stress 1.Growth and seed production response of Commelina communis L.to water stressWater stress is one the important part of environmental factor that limit the plant growth and seed production of plant.Plant response to water stress are a complex phenomenon which involve different morphological changes.Plant height and number of leaves were regressed for both experiments(degree of water stress and duration of water stress)using three parameter sigmoid model.Different degree of water stress response for C.communis L.was 100%,80%,60%,40% and 20% of field capacity(FC).Maximum plant height(85.58 cm)and number of leaves(92.96)with normal plant morphology,high seed and biomass production were recorded for 100% and 80% FC.However,a drastic decline was observed when water stress was increased [(minimum plant height(20.83 cm)and number of leaves(21.87)was observed in 20% followed by 40% FC].Similarly,duration of water stress responses were also considered for C.communis i.e.2,3,4,and 6 days? durations following 100% of field capacity.The results showed an inverse correlation between duration of water stress and C.communis performance.As the duration of water stress was reduced,the plant height,number of leaves,biomass and seed production was increased.This proves that C.communis L.growth and production increases with high water content,whereas water stress significantly decreased its growth and seed production.Results of these experiments concluded that proper water management in cropping system could be an important component to deal with the management of C.communis.2.Growth,biomass partitioning and chlorophyll fluorescence response to drought stress: A comparative study of Commelina communis L.biotypes.Plants continuously adjust to their surroundings to organize the growth and photosynthesis activity in response to environmental fluctuations.The growth and photosynthesis response are mostly achieved by linking multiple environmental signals.Drought stress is one of the environmental setbacks which negatively affects growth and physiological processes.Drought stress was applied to C.communis biotypes to provide the basic information and to detect the efficiency of photosystem II.Three different biotypes of C.communis(JL-1-1,LN-8 and HB-9-1)were compared in this study.These biotypes were treated with 100% field capacity(control)and 60% field capacity followed by 10 days drought stress condition.Under drought stress plant growth,biomass partitioning and chlorophyll fluorescence were significantly decreased in three biotypes as compared to control.In conclusion C.communis biotypes JL-1-1 under drought stress showed a healthy status having a superior photosynthetic capacity than LN-8 and HB-9-1.This study revealed the survival and competitiveness mechanism of C.communis biotypes under drought stress conditions and may serve as a theoretical basis to protect C.communis populations.3.Drought stress response of Commelina communis L.biotypes: a gene expression study.Commelina communis L.is an important weed of many crop,but very little information about the adaptation of C.communis biotypes under drought stress.We investigated five different biotypes of C.communis under drought stress to identify the adaptation mechanism.The expression of drought stress related genes(DRS1,EREB and HRB1)was up-regulated in biotypes,while in some biotypes their expression was down regulated.All five biotypes can thus regulate water balance to consume less water to maintain their status under drought stress condition.This result concluded that C.communis biotypes can survive longer under drought stress condition.Weed scientist should seek more effective management strategies to deal with C.communis.