Plant Productions

Effect of Plant Density on Some Physiological and Phenological Indices of Oat (Avena sativa L.) Genotypes in Climatic Conditions of Ahvaz

Maryam Dolatabadi; Payman Hassibi; Habibolah Roshanfekr Dezfuli; Behzad Sorkhi

Volume 42, Issue 3 , December 2019, , Pages 415-428

https://doi.org/10.22055/ppd.2019.24683.1561

Abstract

Abstract Background and Objectives This study aimed at determining growth indices and temperature requirements at different stages of plant growth in order to optimize the ecology ... Read More Abstract Background and Objectives This study aimed at determining growth indices and temperature requirements at different stages of plant growth in order to optimize the ecology of plants to increase yield due to the availability of appropriate access to many agro technological issues, including appropriate planting dates, timely irrigation, appropriate time of harvesting, proper time to control the pests and diseases, the selection the appropriate cultivars, and achieving the highest yield of crops. The study also aimed at determining the growth indices and the growth rate of oat based on the BBCH scale. Materials and Methods This experiment was conducted in the experimental field of Shahid Chamran University of Ahvaz during 2013-2014 growing season. Five oat genotypes (V1, V2, V3, V4, and V5) were grown under three different planting densities (including 300, 400, and 500 plants.m-2) using factorial experiment based on a randomized complete block design with three replicates. Growing Degree Days (GDD) of the different growing stages, according to the BBCH scale, and the daily temperature were calculated. Several physiological traits such as CGR, relative growth rate (RGR), net assimilation rate (NAR), SPAD value and total dry matter yield were evaluated. Results The treatments had different effects on growth indices and physiological traits such as plant growth rate (CGR), relative growth rate (RGR), net assimilasion rate (NAR), leaf chlorophyll content, chlorophyll meter number, and dry matter yield. The results of the mean comparison showed that V2 had the highest level of NAR, RGR, CGR and TDW among oat genotypes, with an average of 1.40 g.m-2.day-1, 0.0015 g. g-1.da, 6.34 g.m-2.day and 39.87 g.m-2.day respectively, at a density of 300 plants / m2. In contrast, V1 had the lowest total dry matter yield with an average of 22.95 g.m-2 day. Among the genotypes, V2 had the lowest growth period with a density of 300 plants.m-2 with an average of 162 days of planting and 1899 days of growth (GDD in degrees C) and V4 had the highest growth period among the studied genotypes at a density of 500 plants.m-2 with the average of 175 days of sowing and 2178 days of growth. Discussion Reducing CGR at high densities can result in reduced photosynthetic energy in the growth of organs, or increased respiration or poor nutritional transmission of the growth of leaves from the root (Moradpour et al. 2013). Because of the decreasing RGR trend and the increasing density, dry matter accumulation was mainly attributed to undifferentiated tissues, as well as the shading of leaves on each other. Moreover, the increase in the age of the leaves can be considered effective in this decrease. Reductions in NAR during the increase in density can be attributed to the rapid addition of assimilates to seeds and the aging of the leaves. Considering the results of this research, it is suggested that using a GDD scale can lead to better at the growing season by estimating the time table as well as the time of phenological stages of oat in order to manage agricultural production, and therefore to determine the necessary conditions for plant growth.

Evaluation of Sodium Accumulation in Leaves of Wheat (Triticum Aestivum L.) Cultivars Differing in Salt Tolerance

V. Atlassi Pak

Volume 41, Issue 1 , June 2018, , Pages 43-56

https://doi.org/10.22055/ppd.2017.19760.1405

Abstract

Abstract Background and Objectives Two main mechanisms for salt tolerance in plants are low rate of salt transport to shoots and tolerance of high leaf salt concentrations by sequestration ... Read More Abstract Background and Objectives Two main mechanisms for salt tolerance in plants are low rate of salt transport to shoots and tolerance of high leaf salt concentrations by sequestration of Na+ within cells vacuoles. Recently research for genetic variation in Na+ accumulation within bread wheat has revealed large variation in leaf Na+ concentration. The control of Na+ accumulation in leaf is an important physiological process conferring salt tolerance to wheat. Many studies have shown that low sodium concentration in leaves correlate with salt tolerance. Sodium concentration in leaves may be influenced by sodium uptake by roots and transport from root to shoot. Materials and Methods In order to understand the salt tolerance mechanisms and the pattern of Na+ accumulation, 3 bread wheat cultivars differing in salt tolerance (Kavir, Mahdavi and Jajan), were evaluated through two factorial experiments based on completely randomized design in three replications. Experiment 1 used 3 cultivars (Kavir, Mahdavi and Jajan) with four salt treatments (0, 50, 100 and 150 mM NaCl) and experiment 2 used three cultivars (Kavir, Mahdavi and Jajan) with two salt treatments (0 and 150 mM NaCl). Results Leaf Na+ concentration of genotypes was increased in response to increasing salinity after 14 days but Na+ concentration was greater in sensitive genotype (Tajan) than tolerant genotypes (Kavir and Mahdavi). There were no significant differences between genotypes in RGR and shoot: root ratio. Results showed that the differences between genotypes in Na+ transport were responsible for differences in shoot Na+ concentrations. Na+ concentration in the root of all genotypes was the same but salt tolerant genotypes maintained higher K+: Na+ ratio in shoot. Shoot biomass was significantly reduced at 150 mM NaCl, whereas this reduction was almost the same for all genotypes. Kavir had the highest ability to tolerate high leaf tissue concentrations of Na+ and leaf Na+ concentrations were much lower in Mahdavi than two other cultivars. Discussion It seems that the major effect of salinity on shoot biomass was due to the osmotic effect of salt, not due to Na+-specific effects within the plant. Differences in Na+ transport rates from roots to shoots may cause different patterns of sodium accumulation through time. The comparison of genotypes suggests that at least there are two main mechanisms for salt tolerance in hexaploid wheat. One is a lower rate of Na+ accumulation in shoot and the other is tolerance of tissue to high concentrations of Na+.

Investigation in to the phenology stages, some growth indices and qualitative and quantitative characteristics of three potato (Solanum tuberosum L.) cultivars

A. Darabi; A. Eftekhari

Volume 37, Issue 3 , December 2014, , Pages 53-67

Abstract

In order to study phenology, some growth indices and qualitative and quantitative characteristics of potato cultivars (Savalan, Sante and Cozima) an experiment was conducted for one ... Read More

Short-term responses of stomatal conductance for screening wheat cultivars (Triticum aestivum L.( differing in salt tolerance for osmotic stress tolerance

A. Rahnama; K. Poustini; R. Tavakkol Afshari

Volume 36, Issue 3 , December 2013, , Pages 93-105

Abstract

Salinity affects plant growth by the osmotic stress of salt around the roots as well as by toxicity caused by excessive accumulation of salt in leaves. An investigation was set up to ... Read More

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Keywords = Relative growth rate

Effect of Plant Density on Some Physiological and Phenological Indices of Oat (Avena sativa L.) Genotypes in Climatic Conditions of Ahvaz

Abstract

Evaluation of Sodium Accumulation in Leaves of Wheat (Triticum Aestivum L.) Cultivars Differing in Salt Tolerance

Abstract

Investigation in to the phenology stages, some growth indices and qualitative and quantitative characteristics of three potato (Solanum tuberosum L.) cultivars

Abstract

Short-term responses of stomatal conductance for screening wheat cultivars (Triticum aestivum L.( differing in salt tolerance for osmotic stress tolerance

Abstract