scholarly journals Genetic control and combining ability of flag leaf area and relative water content traits of bread wheat cultivars under drought stress condition

Genetika ◽  
2013 ◽  
Vol 45 (2) ◽  
pp. 351-360 ◽  
Author(s):  
Ahmad Golparvar

In order to compare mode of inheritance, combining ability, heterosis and gene action in genetic control of traits flag leaf area, relative water content and grain filling rate of bread wheat under drought stress, a study was conducted on 8 cultivars using of Griffing?s method2 in fixed model. Mean square of general combining ability was significant also for all traits and mean square of specific combining ability was significant also for all traits except relative water content of leaf which show importance of both additive and dominant effects of genes in heredity of these traits under stress. GCA to SCA mean square ratio was significant for none of traits. Results of this study showed that non additive effects of genes were more important than additive effect for all traits. According to results we can understand that genetic improvement of mentioned traits will have low genetic efficiency by selection from the best crosses of early generations. Then it is better to delay selection until advanced generations and increase in heritability of these traits.

Author(s):  
Mainak Barman ◽  
Vinay Kumar Choudhary ◽  
Satish Kumar Singh ◽  
Rabiya Parveen ◽  
Abhishek K. Gowda

Character association studies help in assessing the relationship among yield and its components to enhance the selection utility. In view of this, the present research was carried out for assessing correlation and path coefficients among 30 bread wheat (Triticum aestivum L.) genotypes using fifteen quantitative parameters. Correlation analysis demonstrated a noteworthy positive relationship of days to fifty per cent flowering, number of tillers/plant, flag leaf area, spike length, plant height, chlorophyll content, relative water content, number of grains/ ear, thousand-grain weight, days to maturity and harvest index, with grain yield per plant at both the phenotypic and genotypic level except canopy temperature which showed a significant negative relationship. Path coefficient analysis revealed that plant height, flag leaf area, relative water content and grain per ear had the maximum positive direct effect on grain yield. Hence, the present investigation can be helpful in executing a reliable selection of parental lines based on these above mentioned traits in addition to developing high-yielding varieties for further breeding programme.


Genetika ◽  
2012 ◽  
Vol 44 (1) ◽  
pp. 25-32 ◽  
Author(s):  
Ahmad Golparvar

Mode of gene action, heritability and determination of the effective breeding strategy for improvement of physiological and traits specifically in drought stress conditions is very important. Therefore, this study was conducted by using two drought susceptible and tolerant wheat cultivars. Cultivars Sakha8 (tolerant) and Pishtaz (susceptible) as parents along with F1, F2, BC1 and BC2 generations were sown in a randomized complete block design with three replications in drought stress conditions. Results of analysis of variance indicated significant difference between generations as well as degree of dominance revealed over-dominance for the both traits. Fitting simple additive-dominance model designated that this model was not able to account for changes of traits relative water content and mean of grain filling rate. It was revealed that m-d-h-i-j model for relative water content and m-d-h-i model for mean of grain filling rate are the best models. Estimation of heritability and mode of gene action indicated that selection for improvement of traits studied in stress condition and specifically in early generations have medium genetic gain. In conclusion, grain filling rate is better than relative water content as indirect selection criteria to improve plant grain yield in drought stress condition.


2016 ◽  
Vol 27 (2) ◽  
pp. 128-135 ◽  
Author(s):  
J Akte ◽  
S Yasmin ◽  
MJH Bhuiyan ◽  
F Khatun ◽  
J Roy ◽  
...  

Five rice varieties viz. Binadhan-4, Binadhan-5, Binadhan-6, Binadhan-10 and Iratom-24 were evaluated in vitro under different water stress conditions. Several parameters such as germination percentage, shoot length, root length, shoot-root ratio, fresh weight, dry weight, turgid weight, relative water content and proline accumulation were studied. Drought condition was created by MS medium supplemented with five treatments of PEG, with a control such as 0%, 1%, 2%, 3% and 4% of PEG. The highest germination (100%) was found in the variety Binadhan-10 under low water stress conditions induced by 1% PEG. Similarly, the highest percentage of germination was found in all varieties under control condition (0% PEG). The lowest percentage of germination was obtained in the variety Iratom-24. But under severe stress (4% PEG), the highest percentage of germination was found only in the variety Binadhan-10. Moreover, the variety Binadhan-10 was found to be the best at 4% PEG for shoot length, root length, shoot-root ratio, relative water content and also the best at 1% PEG for fresh weight, dry weight, turgid weight. Water stress decreased relative water content and increased proline accumulation in rice. The highest relative water content was recorded in the variety Binadhan-10 and the lowest value recorded in the variety Binadhan-5. The highest proline content was obtained from the binadhan-6 at the highest treatment (4% PEG). Binadhan-10 showed the best performance almost in all the parameters under drought stress because of its own nature of tolerancy.Progressive Agriculture 27 (2): 128-135, 2016


2004 ◽  
Vol 52 (3) ◽  
pp. 287-296 ◽  
Author(s):  
M. M. Azooz ◽  
M. A. Shaddad ◽  
A. A. Abdel-Latef

The salt tolerance of three sorghum (Sorghum bicolor L.) cultivars (Dorado, Hagen Shandawil and Giza 113) and their responses to shoot spraying with 25 ppm IAA were studied. Salinity stress induced substantial differences between the three sorghum cultivars in the leaf area, dry mass, relative water content and tolerance index of the leaves. Dorado and Hagen Shandawil tolerated salinity up to 88 and 44 mM NaCl, respectively, but above this level, and at all salinity levels in Giza 113, a significant reduction in these parameters was recorded. The rate of reduction was lower in Dorado than in Hagen Shandawil and Giza 113, allowing the sequence Dorado ? Hagen Shandawil ? Giza 113 to be established for the tolerance of these cultivars to salinity. The differences in the tolerance of the sorghum cultivars were associated with large differences in K+ rather than in Na+, which was found to be similar in the whole plant. The youngest leaf was able to maintain a higher K+ content than the oldest leaf. Consequently the K+/Na+ ratios were higher in the most salt-tolerant cultivar Dorado than in the other sorghum cultivars, and in the youngest than in the oldest leaf. In conformity with this mechanism, the stimulatory effect of the exogenous application of IAA was mostly associated with a higher K+/Na+ ratio. Shoot spraying with IAA partially alleviated the inhibitory effect of salinity on leaf growth and on the K+ and Ca2+ contents, especially at low and moderate levels of salinity, while it markedly retarded the accumulation of Na+ in the different organs of sorghum cultivars. Abbreviations: LA: Leaf area, DM: Dry mass, I Indole acetic acid, RWC: Relative water content,TI: Tolerance index


2020 ◽  
Vol 71 (9) ◽  
pp. 2713-2722 ◽  
Author(s):  
Haicui Xie ◽  
Jianqin Shi ◽  
Fengyu Shi ◽  
Haiyun Xu ◽  
Kanglai He ◽  
...  

Abstract Plants are routinely subjected simultaneously to different abiotic and biotic stresses, such as heat, drought, and insect infestation. Plant–insect interactions in such complex stress situations are poorly understood. We evaluated the performance of the grain aphid (Sitobion avenae) in wheat (Triticum aestivum L.) exposed to a combination of heat and drought stresses. We also performed assays of the relative water content, nutritional quality, and responses of phytohormone signaling pathways. Lower relative water content and accumulation of soluble sugars and amino acids were observed in plants exposed to combined heat and drought stress. These conditions increased abscisic acid levels in the absence of aphids, as well as leading to higher levels of jasmonate-dependent transcripts. The grain aphid infestation further increased abscisic acid levels and the abundance of jasmonic acid- and salicylic acid-dependent defenses under the combined stress conditions. Aphids reared on plants grown under drought stress alone showed lower net reproductive rates, intrinsic rates of increase, and finite rates of increase compared with aphids reared on plants in the absence of stress. The heat-treated plants also showed a decreased aphid net reproductive rate. These findings demonstrate that exposure to a combination of stresses enhances plant defense responses against aphids as well as altering nutritional quality.


Author(s):  
K.D. Nkoana ◽  
Abe Shegro Gerrano ◽  
E.T. Gwata

The genetic potential for drought tolerance in cowpea within the small holder sector has not been fully exploited in South Africa. Thus, a drought evaluation experiment was conducted at the ARC-VOP to evaluate 28 cowpea germplasm accessions including two controls viz. IT96D-602 (drought tolerant) and TVU7778 (susceptible to drought) in the drought screening house using plastic box evaluation method in January, 2017. Genotypes raised for three weeks were subjected to 5 weeks of water stress treatment to determine their physiological response through leaf wilting index, relative water content and proline content followed by re-watering to determine genotype (s) with ability to recover from drought stress. Analyses of variance showed highly significant differences in response to moisture stress among the cowpea accessions for the selected physiological traits except for leaf wilting index at week two of drought stress. Stem greenness and recovery appeared to be a reliable indicator of drought tolerant genotypes which was readily observed in Acc1257, Acc1168, Acc2355, IT96D-602 and Acc5352 which also correlated significantly and positively with relative water content and proline content. The genotypes responded differently to drought stress indicating that there is sufficient genetic variability that can be utilized further in breeding for drought stress within the cowpea species.


2014 ◽  
Vol 61 (4) ◽  
pp. 493-506 ◽  
Author(s):  
Maryam Goodarzian Ghahfarokhi ◽  
Syrus Mansurifar ◽  
Ruhollah Taghizadeh-Mehrjardi ◽  
Mohsen Saeidi ◽  
Amir Mohammad Jamshidi ◽  
...  

2019 ◽  
Vol 6 (2) ◽  
pp. 183-189
Author(s):  
Adewole Adebusola ◽  
Odjegba Victor ◽  
Iwuala Emmanuel ◽  
Afroz Alam

Nitrogen is an important nutrient for the successful metabolism of plants, but its occurrence in soil is always very limited. This nutrient has a significant role to preserve plants during various stress conditions by altering the production rate of phytochemicals as defense weapons. Hence, this study was carried out to analyze the effect of nitrogen supply on the phytochemical composition and relative water content in Jatropha curcas L. under a simulated drought condition. The selected seedlings were grown from stem cuttings and categorized into different treated three groups along with the control. After the completion of the experiment, the growth pattern and phytochemical production were investigated. An increased malondialdehyde activity (MDA) was reported with a reduction in relative water content (RWC) of the leaf and in the biomass of seedlings under drought stress. A significant decrease in the levels of alkaloids, phenol, flavonoids and tannins with an increase in saponins and terpenoids was also observed in only simulated drought stressed plants. While a significant increase in the levels of total alkaloid, tannins, flavonoids and phenols was observed in those plants where exogenous nitrogen was supplied before the start of drought periods, unlike in treated and control plants. Therefore, it was revealed that application of Nitrogen enabled the plants to possess protective mechanism through the production of phytochemicals that facilitate the cell membrane to reduce the detrimental effects caused by drought stress.


2021 ◽  
Vol 108 (june) ◽  
pp. 1-4
Author(s):  
Devi M ◽  
◽  
Vincent s ◽  
Babu Rajendra Prasad ◽  
Anandham R ◽  
...  

High temperature is a critical barrier in most cotton growing areas, limiting cotton growth and development. The present study aimed to evaluate the effects of foliar spray on KC 3 cotton variety grown under ambient (32.66°C) and high temperature (37.21°C) stress in open-top chamber (OTC) with a temperature of 5°C from the ambient temperature for 10d from flowering to boll development stage. Foliar spray of kaolin @ 3% and calcium carbonate @ 5% were sprayed separately to the set of pots both in ambient and elevated temperature on 70th day of flowering. Observations on morphological and physiological parameters were recorded on viz., plant height (cm plant-1), leaf area (cm2 plant-1), relative water content (%), canopy temperature (°C), SPAD, chlorophyll fluorescence (Fv/Fm ratio). Kaolin @ 3% foliar spray significantly increased the plant height, leaf area, relative water content, chlorophyll content and reduced the canopy temperature both in high temperature and ambient temperature conditions. Among these treatments, T2 - kaolin 3% (Ambient) followed by T5 - Kaolin 3% (elevated temperature of 5 °C) recorded higher values as compared to calcium carbonate treatment both in ambient temperature and high temperature condition.


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