Showing 2 results for Genotypes.
B. Sharifnabi, G. Saeidi,
Volume 8, Issue 3 (10-2004)
Abstract
Safflower (Carthamus tinctorius L.) is one of the multi-purpose oilseed crops which has a high adaptation to different conditions such as resistance to drought and it is suited to be grown in arid and semi-arid regions such as Isfahan province. Root rot disease is an important soil-borne disease of safflower in Isfahan, which can be caused by different pathogens. The objective of this study was to determine the causal agent of safflower root rot and to evaluate different genotypes for tolerance to the disease. Different species of Fusarium were isolated from sample collections. Laboratory and greenhouse inoculations indicated that F. solani was the only pathogenic species. In this experiment, 60 genotypes of safflower including breeding lines selected from various Iranian local populations and foreign cultivars were evaluated for reaction to the disease in a randomized complete block design with three replications in greenhouse. Artificial inoculation via injection of spore suspension of F. solani (106 spores/ml) was conducted on 8-week plants and then development of necrosis and death percentage were recorded. The results showed that there were significant differences among the genotypes in terms of reaction to the disease. The most resistant and susceptible genotypes were breeding lines of IUTE14310 and IUTC121 with mean necrosis of 9.67 and 28.33 mm, and death percentage of 32 and 74, respectively. Based on the means of necrosis and death percentage, the genotypes were significantly classified in 5 distinct groups including resistant (7 genotypes), moderately resistant (19 genotypes), tolerant (29 genotypes), moderately susceptible (3 genotypes), and susceptible (2 genotypes). The commercial foreign cultivars of AC Sunset, AC Sterling belonged to tolerant and moderately susceptible groups, respectively. However, Saffire was classified as a tolerant genotype. The local landrace of Kooseh which is widely grown in Isfahan province was classified as susceptible genotype. Phenotypic and genetic coefficients of variation (23.85 and 18.32 %, respectively) and a relatively high broad-sense heritability (59%) for necrosis and also the phenotypic and genetic coefficients of variation (25 and 21 %, respectively) and a high broad-sense heritability (73%) for death plants indicated that there was sufficient genetic variation for resistance and selection can be effective for producing resistant genotypes to Fusarium root rot disease.
S. Abdi Ardestani, B. Khalili, M. M. Majidi,
Volume 25, Issue 1 (5-2021)
Abstract
Long-term drought effect is one of the main factors of global climate change, with consequences for soil biogeochemical cycling of carbon and nitrogen and the function of soil ecosystem under drought conditions. We hypothesized that 1) the Bromus inermis, Dactylis glomerata and festuca arundinacea species would differ in their rhizosphere responses to drought and 2) combined plant species and drought would have offsetting effects on the soil biological traits. We tested these hypotheses at the long-term drought field expreiment at the Lavark Farm of Isfahan University of Technology by analyzing soil microbial biomass carbon and nitrogen and activity of β-glucosaminidase in the rhizosphere of Bromus inermis, Dactylis glomerata and festuca arundinacea species. Soil microbial biomass carbon and nitrogen responses to drought depended on plant species, such that the highest MBC was recorded in the Bromus inermis rhizosphere, while the lowest was in the Dactylis glomerata rhizosphere, thereby suggesting the greater microbial sensitivity to drought in the Dactylis glomerata rhizosphere. Genotype variations (drought tolerate and sensitive) mostly affected the change in the β-glucosaminidase activity, but they were not significantly affected by drought treatment and plant species. In general, the positive effects of the plant genotype could offset the negative consequences of drought for soil microbial biomass and traits.
