Combining Drought and Aluminum Toxicity Tolerance To Improve Sorghum Productivity

Moisture stress and aluminium toxicity in sorghum production can be overcome by breeding for tolerance. This study was set up to determine the response of sorghum (Sorghum bicolor L.) genotypes to post- anthesis drought and aluminium toxicity. Sorghum inbred P1 with stay green drought tolerance was crossed with P2, a standard aluminium tolerant cultivar. The parents, the first filial plants (F1) and KM-4 were tested for drought and aluminium toxicity tolerance in the field and solution culture with 0 and \u3bcMol 148 Al3+ respectively. The drought experiment was laid in RCBD with three replicates and split -plot arrangement. Randomly selected plots were denied irrigation from six weeks after emergence. There were significant (P < 0.05) differences between treatments and accessions. Panicle weight of F1 was outstanding and significantly different from the rest both with and without water. F1 out performed P1, P2 and KM-4 by 95.61, 146.37 and 328.81% without water; and by 155.44, 124. 27 and 82.02% with water, respectively. There were significant (P < 0.05) differences in the sorghum accessions with P2, KM-4 and F1 being tolerant. These results indicate that multiple stress tolerance can increase sorghum productivity.Le stress hydrique et la toxicit\ue9 aluminique dans la production de sorgho peuvent \ueatre surmont\ue9s par am\ue9lioration de la tol\ue9rance. Cette \ue9tude \ue9tait faite dans le but de d\ue9terminer la r\ue9ponse des g\ue9notypes du sorgho (Sorghum bicolor L.) \ue0 la s\ue9cheresse post-anth\ue9sis et la toxicit\ue9 aluminique. Le sorgho de lign\ue9e pure P1 dot\ue9 d'une persistence chlorophyllienne caract\ue9risant sa tol\ue9rance \ue0 la s\ue9cheresse, \ue9tait crois\ue9 avec P2, un cultivar de tol\ue9rance standard \ue0 l'aluminium. Les parents, les premi\ue8res plantes filiales (F1) et KM-4 \ue9taient test\ue9s au champs et avec une solution de culture 0 et 148 Al3+ \u3bcMol respectivement pour tol\ue9rance \ue0 la s\ue9cheresse et \ue0 la toxicit\ue9 aluminique. Le dispositif experimental de l'essai sur la s\ue9cheresse \ue9tait en blocs al\ue9atoires compl\ue9tement randomis\ue9s avec trois r\ue9p\ue9titions et un arrangement en split-plot. Les parcelles al\ue9atoirement s\ue9lectionn\ue9es n'\ue9taitent pas arros\ue9es depuis six semaines apr\ue8s \ue9mergence. Des diff\ue9rences significatives (P < 0.05) \ue9taient observ\ue9es entre traitements et accessions. Le poids des panicules de F1 \ue9tait exceptionnellement diff\ue9rent de celui avec ou sans eau. F1 avait \ue9t\ue9 plus performant que P1, P2 et KM-4 avec 95.61, 146.37 et 328.81 % sans eau; et avec 155.44, 124. 27 et 82.02 % avec eau, respectivement. De diff\ue9rences significatives (P < 0.05) \ue9taient aussi r\ue9v\ue9l\ue9es entre les accessions de sorgho, le parent P2, les accessions KM-4 et les plants F1 \ue9tant tol\ue9rants. Ces r\ue9sultats indiquent que la tol\ue9rance multiple au stress peut augmenter la productivit\ue9 du sorgho

Cell membrane integrity, callose accumulation, and root growth in aluminum-stressed sorghum seedlings

Aluminum stress usually reduces plant root growth due to the accumulation of Al in specific zones of the root apex. The objectives of this study were to determine the localization of Al in the root apex of Sorghum bicolor (L.) Moech. and its effects on membrane integrity, callose accumulation, and root growth in selected cultivars. Seedlings were grown in a nutrient solution containing 0, 27, or 39 μM Al3+ for 24, 48, and 120 h. The Al stress significantly reduced root growth, especially after 48 and 120 h of exposure. A higher Al accumulation, determined by fluorescence microscopy after staining with a Morin dye, occurred in the root extension zone of the sensitive cultivar than in the tolerant cultivar. The membrane damage and callose accumulation were also higher in the sensitive than resistant cultivar. It was concluded that the Al stress significantly reduced root growth through the accumulation of Al in the root extension zone, callose accumulation, and impairment of plasma membrane integrity

Effects of lime, phosphorus and rhizobia on Sesbania sesban performance in a Western Kenyan acid soil

Aluminium (Al) toxicity, phosphorus (P) deficiency and low rhizobia populations limit Sesbania (Sesbania sesban) performance in tropical acid soils. The study determined the i) indigenous rhizobia populations that nodulate sesbania and ii) effects of lime (0 and 4 t/ha), P-fertilizer (0 and 60 kg/ha) and acid tolerant rhizobia (0 and inoculation) on soil and selected sesbania accessions performance in Western Kenya acid soil. Study site had acid soil, low available P, nitrogen (N) and rhizobia populations that nodulate Sesbania (146 cells/g soil). Lime increased soil pH, while both lime and P-fertilizer increased available P. Aluminium toxicity tolerant and P-efficient accessions (SSBSA004, SSUG3, SSUG4 and SSUG5) had faster growth, higher nodulation, shoot P, and shoot N and response to treatments than the sensitive one (SSBSA203). After 7 months of growth, SSUG3 had highest shoot length (306 cm) and dry matter (5.64 tons/ha), hence, most suitable for building poles and fuel wood. SSUG5 accumulated the highest shoot N (222 kg N/ha) and was therefore, most suitable soil N replenishment. Thus, in acid P deficient and low rhizobial population soils of Western Kenya, the use of lime, P-fertilizer, rhizobia inoculation and Al toxicity tolerant Sesbania are important for Sesbania establishment and growth. Key words: Rhizobia, Sesbania, soil acidity, aluminum toxicity, lime, phosphorus

Combining Drought and Aluminum Toxicity Tolerance To Improve Sorghum Productivity

Moisture stress and aluminium toxicity in sorghum production can be overcome by breeding for tolerance. This study was set up to determine the response of sorghum (Sorghum bicolor L.) genotypes to post- anthesis drought and aluminium toxicity. Sorghum inbred P1 with stay green drought tolerance was crossed with P2, a standard aluminium tolerant cultivar. The parents, the first filial plants (F1) and KM-4 were tested for drought and aluminium toxicity tolerance in the field and solution culture with 0 and μMol 148 Al3+ respectively. The drought experiment was laid in RCBD with three replicates and split -plot arrangement. Randomly selected plots were denied irrigation from six weeks after emergence. There were significant (P < 0.05) differences between treatments and accessions. Panicle weight of F1 was outstanding and significantly different from the rest both with and without water. F1 out performed P1, P2 and KM-4 by 95.61, 146.37 and 328.81% without water; and by 155.44, 124. 27 and 82.02% with water, respectively. There were significant (P < 0.05) differences in the sorghum accessions with P2, KM-4 and F1 being tolerant. These results indicate that multiple stress tolerance can increase sorghum productivity.Le stress hydrique et la toxicité aluminique dans la production de sorgho peuvent être surmontés par amélioration de la tolérance. Cette étude était faite dans le but de déterminer la réponse des génotypes du sorgho (Sorghum bicolor L.) à la sécheresse post-anthésis et la toxicité aluminique. Le sorgho de lignée pure P1 doté d&apos;une persistence chlorophyllienne caractérisant sa tolérance à la sécheresse, était croisé avec P2, un cultivar de tolérance standard à l&apos;aluminium. Les parents, les premières plantes filiales (F1) et KM-4 étaient testés au champs et avec une solution de culture 0 et 148 Al3+ μMol respectivement pour tolérance à la sécheresse et à la toxicité aluminique. Le dispositif experimental de l&apos;essai sur la sécheresse était en blocs aléatoires complétement randomisés avec trois répétitions et un arrangement en split-plot. Les parcelles aléatoirement sélectionnées n&apos;étaitent pas arrosées depuis six semaines après émergence. Des différences significatives (P < 0.05) étaient observées entre traitements et accessions. Le poids des panicules de F1 était exceptionnellement différent de celui avec ou sans eau. F1 avait été plus performant que P1, P2 et KM-4 avec 95.61, 146.37 et 328.81 % sans eau; et avec 155.44, 124. 27 et 82.02 % avec eau, respectivement. De différences significatives (P < 0.05) étaient aussi révélées entre les accessions de sorgho, le parent P2, les accessions KM-4 et les plants F1 étant tolérants. Ces résultats indiquent que la tolérance multiple au stress peut augmenter la productivité du sorgho

Biologia planturum-sept 2014

Aluminum stress usually reduces plant root growth due to the accumulation of Al in specific zones of the root apex. The objectives of this study were to determine the localization of Al in the root apex of Sorghum bicolor (L.) Moech. and its effects on membrane integrity, callose accumulation, and root growth in selected cultivars. Seedlings were grown in a nutrient solution containing 0, 27, or 39 μM Al3+ for 24, 48, and 120 h. The Al stress significantly reduced root growth, especially after 48 and 120 h of exposure. A higher Al accumulation, determined by fluorescence microscopy after staining with a Morin dye, occurred in the root extension zone of the sensitive cultivar than in the tolerant cultivar. The membrane damage and callose accumulation were also higher in the sensitive than resistant cultivar. It was concluded that the Al stress significantly reduced root growth through the accumulation of Al in the root extension zone, callose accumulation, and impairment of plasma membrane integrity

Fatigue in psoriatic arthritis - a cross-sectional study of 246 patients from 13 countries

Objectives: Fatigue is an aspect of psoriatic arthritis (PsA), which is important to patients. The objective was to evaluate magnitude of fatigue in PsA patients and to assess factors that might explain high levels of fatigue. Methods: This was an ancillary analysis of a cross-sectional study in 13 countries of unselected PsA patients who fulfilled the CASPAR criteria. Patient-perceived importance of fatigue was assessed through a priority exercise. Levels of fatigue were assessed by a numeric rating scale (range 0–10). Factors potentially associated with fatigue > 5/10: i.e., demographic variables (age, gender, disease duration, education level) and disease related characteristics including joint counts, C-reactive protein, skin psoriasis, axial involvement, enthesitis, dactylitis, structural damage, were assessed by univariate, multivariate logistic and multiple linear regression. Results: In all, 246 patients were analysed: mean ± standard deviation age 51.2 ± 13.0 years, mean disease duration 9.9 ± 10.1 years, mean DAS28 3.5 ± 1.3. Fatigue was ranked second in patient-perceived importance, after pain. Magnitude of fatigue was high: mean fatigue 5.0 ± 3.0. Fatigue > 5/10 was well explained (variance explained 73%) by skin psoriasis (odds ratio 4.67 [95% confidence interval 1.05; 20.72]), tender joints (1.30 [1.01; 1.68]) and lower education level (1.09 [1.02; 1.23]). In the multiple linear regression model, fatigue was explained by skin psoriasis, tender joints, enthesitis, female gender, education level. Conclusions: Fatigue is a priority for PsA patients. Fatigue levels were high in these patients and fatigue > 5/10 was mainly associated with disease-related factors but also patient-related variables, indicating that the etiology of fatigue in PsA is multifactorial