Showing 2 results for Root Surface.
Hamid Reza Eshghizadeh, Shahram Riyahinia, Hamid Reza Khazaei,
Volume 5, Issue 1 (3-2014)
Abstract
Plant roots, with respect to their intrinsic characteristics, have important role in both improvement and development of germplasms of drought resistant plants. This experiment was conducted to study direct and indirect effects of root morphological traits on grain yield of four triticale genotypes (three promising lines of ET-82-8, ET-82-15 and
ET-79-17 along with the conventional Junillo-92 cultivar) under two available moisture levels in soil (irrigation after 50% moisture depletion in the root zone, as control) and moisture stress (irrigation after 80% moisture depletion in the root zone) as a randomized complete blocks design in factorial arrangement with four replications, in Research Greenhouse of College of Agriculture, Ferdowsi University, Mashhad, Iran, in 2008. The results showed that water stress caused a 9% reduction in root depth development. Also, the difference between deepest root in ET-82-15 and the shallowest root in Junillo-92 was about 8.2 cm. Delay in irrigation caused a 25% reduction in accumulated root length. The 43% difference between highest accumulated root length in ET-82-15 and lowest accumulated root length in ET-79-17 was significant at 1% level. The role of root morphology of these genotypes on seed production was different under various soil moisture conditions. In optimum soil water content, direct effect of accumulated root length with regression coefficient of 0.543 was more than water deficit conditions with regression coefficient of 0.286. On the other hand, direct relation of total root surface with grain yield was negative in normal moisture conditions and negative under water deficit. In general, it seems that accumulated root length and root surface are effective characteristics in seed production of these genotypes total root surface has more important role in water deficit conditions, and accumulated root length in optimum soil moisture levels.
E. Karimi, N. Alisgharzad, S. B. Mousavi, A. Aliloo,
Volume 13, Issue 2 (9-2022)
Abstract
Under water stress conditions, growth-promoting rhizobacteria could alter root characteristics, leading to increased plants yield. A controlled experiment with two barley cultivars, Dasht, and Kavir, was carried out with four inoculations of Bacillus simplex strains (31-2, 42-3, 51-4, and control), in two irrigation levels of 80 and 50% of field capacity. The results showed that inoculation with the mentioned bacteria increased the biological yield of barley by 28% under water stress condition compared to the control treatment. The effect of bacteria was cultivar dependent. B. simplex 31-2 had the most significant effect on the biological yield of Kavir cultivar, and B. simplex 42-3 on the Dasht cultivar. Linear relationships between root characteristics and barley's biological yield were observed. The highest coefficients of determination (R2) were obtained with fresh root weight (84%), root volume (83%), and root surface (81%). Considering the relationship between root traits and the biological yield of barley and the role of B. simplex 31-2 in a 121% increase in root area under water stress, it seems that this trait is the essential mediator of yield. Due to the insignificance effect of B. simplex 3-32 on the root characteristics, against the increase of shoot performance by this bacterium, its mode of action may be due to inducing improvement on other physiological pathways. Overall Bacillus bacteria are effective in mitigating the negative effect of water stress on barley and these bacteria can be considered effective candidates for the production of biofertilizers.
