Differential growth, physiological and biochemical responses of niger (Guizotia abyssinica Cass.) cultivars to water-deficit (drought) stress

Abstract

The present study demonstrates the effect of polyethylene glycol-8000 (PEG) and percent field capacity (FC%)-induced water-deficit stress on growth, water status, productivity and various biochemical parameters in Guizotia abyssinica Cass. cultivars (IGP 76, GA 10, No. 71 and IGPN 2004) at seedling and maturity stages of the plant. Cultivar GA 10 showed higher, IGP 76 and No. 71 moderate, and IGPN 2004 least reduction in percent seed germination given PEG stress treatments (0, 10 and 20%). A similar pattern was observed for decreased growth and water content of the seedlings and plants of the cultivars exposed to both kinds of water-deficit stresses. The productivity (number of capitula per plant, number of seeds per capitula and 1,000-seed weight) and total chlorophyll content of cultivar IGPN 2004 was significantly higher in comparison to other cultivars given different FC% treatments (100, 80 and 60%). Significantly higher accumulation of proline, glycine betaine and total soluble sugars and lower damage to membrane lipids under increased waterdeficit stress (i.e., at 80 and 60% FC) conditions in cultivar IGPN 2004 suggested its more tolerance capacity to waterdeficit stress in comparison to other cultivars. Besides, antioxidant enzyme activities (superoxide dismutase, catalase, ascorbate peroxidase and guaiacol peroxidase) partially demonstrated variations in the tolerance of the cultivars to water-deficit stress. The results suggest that cultivar IGPN 2004 could be considered as more tolerant, and IGP 76 and No. 71 as moderately tolerant, whereas GA 10 was more sensitive to water-deficit stress.

Drying Kinetics of Niger Seeds

“…Oleaginous plants have been introduced as winter crops in Brazil, especially in the CentralWest region of the country, in areas previously under fallow; thus, niger ranging from 30% to 40% in oil content (Ghane et al, 2012;Ramadan 2012) has a great potential to be cultivated in this region (Gordin et al, 2012). The oil from niger seeds can be used for several industrial purposes, such as making soaps, paints, and lubricants, and can also be used as raw material in biodiesel production.…”

Influence of hydrogel on germination of lettuce and onion seed at different moisture levels

“…The above mentioned results suggest that the cultivar (and its vigour) is an important factor aff ecting sensitivity (respectively adaptability) of seeds to the moisture defi cit. The importance of cultivars with regards to drought stress tolerance is mentioned by GHANE et al (2012) at Guizota abyssinica Cass., or ENNAJEH et al (2009) at Olea europaea L. These varieties, which are more tolerant to water defi ciency, have better potential for use in extensive vegetable production systems with limited irrigation.…”

Glyphosate Plus Carboxylic Compounds Boost Activity of Free Radical-Scavenging Enzymes in Sugarcane

“…While it appears that excessive concentration of ROS damages the plant, low levels are part of signaling mechanisms that acclimate to biotic and abiotic stresses [11][12][13]. Experts seriously rely on the enhancement of the plant stress defense system as the real key to providing agriculture with productivity and quality of food, energy, fiber and raw materials [14][15][16][17][18][19]. Scientific studies on the effects of stressful factors on the physiological, histological and developmental behavior of crop plants report ascorbic acid, polyethylene glycol and herbicides are organic and inorganic substances, highly effective in making plant stress defense system healthier and extremely reactive to free radicals [20][21][22].…”