Asian J Agric & Biol

Muhammad Abbas*, Muhammad Irfan, Javaid Ahmed Shah, Muhammad Yousuf Memon

Soil and Environmental Sciences Division, Nuclear Institute of Agriculture (NIA), Tando Jam, Sindh, Pakistan

Abderrahmane Benhmimou¹*, Mohammed Ibriz¹, Chaouki Al Faïz², Fatima Gaboun²,

Naima Shaimi², Fatima Zahra Amchra³, Mounira Lage²

¹Genetic and Biometry Lab, Faculty of Sciences, Ibn Tofail University, P.O. Box 133, 14000, Kenitra, Morocco

²Regional Center of Agricultural Research, P.O. Box 6356, Avenue Mohamed Belarbi Alaoui, 10101 Rabat, Morocco

³Laboratory of Materials, Environment and Electrochemistry, Faculty of Sciences, Ibn Tofail University, P.O. Box 133, 14000, Kenitra, Morocco

Abstract

Since no information is available about the response of stevia (Stevia rebaudiana Bertoni) to water stress under Moroccan conditions. This study was aimed at evaluating the effects of water stress on growth, yield, quality and physiological responses of two stevia varieties (Canada and Candy). Three water regimes were applied: R100 (100% of field capacity (FC)), R80 (80% of FC) and R50 (50% of FC) as determined by pot weight. Water stress significantly reduced stomatal conductance (Gs), photosynthetic rate (A) and transpiration rate (E) by 72.50%, 78.54% and 74.45 % at R50, respectively as compared to R100. With the continuing of water stress time, plant allocated less plant height leading to reductions of 20.27% at R50 as compared to R100. All of the above responses led to reduced dry leaf yield. By contrast, the stevioside, rebaudioside A and total steviol glycoside contents were increased in R50 stevia leaves than R100 (23.58%, 13.50% and 11.73%, respectively). The cv Candy displayed a higher dry leaf yield (34.33 g/plant) and leaf physiological responses compared to cv Canada, which experienced a great decrease. By contrast, the cv Canada recorded a higher total steviol glycoside content (19.63%) than the cv Candy (12.63%). The interaction effects indicate that cv Candy, for R100, displayed a greater dry leaf and SG yields, while these parameters were greatly reduced under R80 and R50. By contrast, the cv Canada always showed a lower dry leaf and steviol glycoside yields and a greater total steviol glycoside contents, that enable it to have a better adaptation to water stress conditions. The variation of cv Canada and cv Candy responses to water stress suggested the higher adaptation of cv Canada to water stress compared to cv Candy.

Keywords: Stevia, Water stress, Steviol glycoside, Leaf physiological responses

Marulak Simarmata*¹, Puji Harsono¹, Hartal Hartal²

¹Department of Agronomy, University of Bengkulu, Indonesia, 38371

²Department of Plant Protection, University of Bengkulu, Indonesia, 38371

Abstract

Mixing of herbicide compounds in one formulation is one way to prevent weed resistance, but it may increase herbicide persistence in the soil and cause eco-toxicity. The research was aimed to evaluate the sensitivity of legumes and the response of soil microorganisms to the residue of the herbicide mixture of atrazine and mesotrione. Herbicide mixture was applied on the soil surface in polybags at 0, 0.125, 0.25, 0.5, 1.0, and 2.0 x field rate (FR). Seeds of soybean, yard long bean, peanut, and mung bean were planted 2 weeks after herbicide application and grown in greenhouse for 4 weeks. Planting legumes was repeated in the same polybag at 8 and 14 weeks after herbicide application. The trials were arranged in a completely randomized design with three replications. Data observed were subjected to analysis of variance and means were further separated by LSD test (P ≤ 0.05). Harmful effects of herbicide residues on legumes seedlings identified ascrop injury (CI), decreased greenness level of leaves (GLL), and decreased dry biomass weight (DBW) were observed at 2 and 8 weeks after application. After 14 weeks, CI and decreased GLL were evident only on soybean, but DBW of legume seedlings was remaining depressed. Similarly, a population of soil bacteria and fungi enumerated as colony forming unit (CFU) per gram of soil were inhibited up to 18 weeks. Efficacy of herbicide residues (EHR) counted as percent of reduction of DBW and CFU on legumes and microorganisms, respectively, were stronger by increasing the rates of herbicide applied andthe EHR persisted until 18 weeks after herbicide application.

Keywords: Atrazine, Ecotoxicity, Herbicide carryover, Legumes, Mesotrione

Amir Hameed^1*, Shabih Fatma², Muhammad Noman¹, Temoor Ahmed¹, Javed Iqbal Wattoo³

¹Department of Bioinformatics and Biotechnology, Government College University, Faisalabad, Pakistan

²National Institute for Biotechnology and Genetic Engineering, Faisalabad, Pakistan

³Faculty of Life Sciences, University of Central Punjab, Lahore, Pakistan

Abstract

Among biotic stresses afflicting potato plants, viruses are the most damaging and are responsible for large economic losses worldwide. Co-infections with multiple viruses are common in potato, with an enhanced disease impact being observed in affected plants. RNA interference (RNAi) provides an applied methodology to selectively reduce the expression of targeted genes through the expression of sequence-specific short interfering RNAs (siRNAs). This silencing mechanism can be implemented to induce resistance against multiple viruses in transgenic plants through the endogenous delivery of siRNA cassettes. The current study was aimed to identify the efficient siRNA execution sites in dominating viral genomes to simultaneously target both DNA and RNA viruses in potato. To achieve this objective, we followed a computational approach to identify the viral silencing targets by comparative pairwise sequence analysis of different isolates of Potato leafroll virus (PLRV; + single-stranded (ss) RNA virus) and Tomato leaf curl New Delhi virus (ToLCNDV; ssDNA virus). The identified consensus sequences [300bp of PLRV-coat protein (CP); 180bp of ToLCNDV-precoat protein (AV2)] were further used as template sequences to predict the likely siRNAs execution sites and to characterize their putative thermodynamic attributes. The identified template sequences were computationally tested for triggering a siRNA-mediated targeting of viral genomes and proved to be highly efficient and site-specific. This methodology could be applied for engineering an RNAi-mediated virus resistance in transgenic plants with commercial applications.

Keywords: Potato, RNAi, Resistance, siRNA, Virus

Tag Archives: 6(1)

Intra-specific variations among wheat genotypes for phosphorus use efficiency

Effects of water stress on growth, yield, quality and physiological responses of two stevia (Stevia rebaudiana Bertoni) varieties in Rabat region, Morocco

Sensitivity of legumes and soil microorganisms to residue of herbicide mixture of atrazine and mesotrione

A computational approach to execute siRNA generating hotspots targeting dual DNA and RNA viral infections in potato

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