Rising atmospheric CO2 concentrations are known to influence the response of many plants under drought. This paper aimed to measure the leaf gas exchange, water use efficiency, carboxylation efficiency, and photosystem II (PS II) activity of Datura stramonium under progressive drought conditions, along with ambient conditions of 400 ppm (aCO2) and elevated conditions of 700 ppm (eCO2). Plants of D. stramonium were grown at 400 ppm and 700 ppm under 100 and 60% field capacity in a laboratory growth chamber. For 10 days at two-day intervals, photosynthesis rate, stomatal conductance, transpiration rate, intercellular CO2 concentration, water use efficiency, intrinsic water use efficiency, instantaneous carboxylation efficiency, PSII activity, electron transport rate, and photochemical quenching were measured. While drought stress had generally negative effects on the aforementioned physiological traits of D. stramonium, it was found that eCO2 concentration mitigated the adverse effects of drought and most of the physiological parameters were sustained with increasing drought duration when compared to that with aCO2. D. stramonium, which was grown under drought conditions, was re-watered on day 8 and indicated a partial recovery in all the parameters except maximum fluorescence, with this recovery being higher with eCO2 compared to aCO2. These results suggest that elevated CO2 mitigates the adverse growth effects of drought, thereby enhancing the adaptive mechanism of this weed by improving its water use efficiency. It is concluded that this weed has the potential to take advantage of climate change by increasing its competitiveness with other plants in drought-prone areas, suggesting that it could expand into new localities.
Parental RNAi (pRNAi) is a response of RNA interference in which treated insect pests progenies showed a gene silencing phenotypes. pRNAi of CmGNA gene has been studied in Cnaphalocrocis medinalis via injection. Our results showed significant reduction in ovulation per female that was 26% and 35.26% in G1 and G2 generations, respectively. Significant reduction of hatched eggs per female were observed 23.53% and 45.26% as compared to control in G1-G2 generations, respectively. We also observed the significant variation in the sex ratio between female (40% and 53%) in G1-G2 generations, and in male (65%) in G1 generation as compared to control. Our results also demonstrated the significant larval mortality (63% and 55%) and pupal mortality (55% and 41%), and significant reduction of mRNA expression level in G1 and G2 generations. Our findings have confirmed that effectiveness of pRNAi induced silencing on the CmGNA target gene in G1-G2 generations of C. medinalis. These results suggested the potential role of pRNAi in insect pest resistance management strategies.
Glucosamine 6-Phosphate N-Acetyltransferase/genetics , Insect Control/methods , Moths/genetics , RNA Interference , Animals , Female , Male , Phenotype , Reproduction
Horse purslane (Trianthema portulacstrum L.) is an important weed of soybean crop capable of causing significant yield reduction. Therefore, this study assessed the impact of horse purslane and other weeds' infestation on the productivity of soybean. Ten treatments, i.e., weed-free throughout the growing season, horse purslane-free till 20, 40 and 60 days after emergence (DAE), all weeds-free till 20, 40 and 60 DAE, weedy-check (excluding horse purslane), weedy-check (horse purslane alone) and weedy-check (all weeds) were included in the study. Data relating to density and dry weight of recorded weed species, and yield and related traits of soybean were recorded. Overall, infestation percentage of horse purslane was 33.10 and 51%, whereas dry weight was 12 and 44 g m-2 during 1st and 2nd year, respectively. The highest dry weight of all weed species was recorded at 45 DAE in weedy-check all weeds treatment during both years. The lowest relative density and frequency of horse purslane were recorded in the treatment where it was controlled until 20 DAE during 2018 at 30 DAE, whereas the same treatment recoded the lowest density of horse purslane at 45 DAE during 2019. The relative frequency of horse purslane was non-significant for weedy-check horse purslane and weedy-check all weeds treatments during 2018, whereas former treatment had higher relative frequency of horse purslane in weedy-check all weeds than the later during 2019. Yield and related traits significantly differed among different treatments used in the study. The treatment all weeds controlled until 40 DAE recorded higher number of pods per plant, 1000-seed weight and seed yield during both years. The yield reduction in weedy-check treatments was; weedy-check all weeds > weedy-check all weeds except horse purslane > weedy-check horse purslane only. It is concluded that horse purslane was not the sole weed interfering soybean fields and weed flora consisted of false amaranth [Digera muricata (L.) Mart.] and purple nut sedge (Cyperus rotundus L.). Hence, if the soybean fields in northern irrigated plains of Pakistan are infested with horse purslane or heavily infested with horse purslane or other weeds, these should be controlled in initial 40 DAE to improve soybean productivity.
Agricultural Irrigation , Ecosystem , Glycine max/physiology , Introduced Species , Portulaca/physiology , Biomass , Climate , Pakistan , Seasons , Glycine max/growth & development
Understanding the impact of irrigation and fertilizer on rabbiteye blueberry (Vaccinium virgatum) physiology is necessary for its precision planting. Here, we applied varied irrigation and fertilizer under completely randomized experimental design to see its impact on the physiological characteristics and bush growth of rabbiteye blueberries. A comprehensive evaluation of the membership function was used to establish the best water-fertilizer coupling regimes. Rabbiteye blueberry enhanced the net photosynthetic rate, stomatal conductance and transpiration rate of leaf and improved its photosynthetic capacity at maximum level of irrigation water and fertilizer application (F3W4). The high fertilizer-medium water treatment (F3W3) increased leaf-soluble protein contents. The medium fertilizer-medium water treatment (F2W3, F2W2) increased leaf- soluble sugar, superoxide dismutase, and chlorophyll contents; decreased the malondialdehyde content; and enhanced leaf resistance and metabolism. It also promoted the growth of flower buds and new shoots. Combined membership function and cluster analyses revealed that the optimal water and fertilizer conditions for promoting rabbiteye blueberry plant growth were the medium fertilizer-medium water [(NH4)2SO4:Ca(H2PO4)2:K2SO4 at 59:10:20 g plant-1; 2.5 L water plant-1], medium fertilizer-medium-high water [(NH4)2SO4:Ca(H2PO4)2:K2SO4 at 59:10:20 g plant-1; 3.75 L water plant-1], and high fertilizer-medium-high water [(NH4)2SO4:Ca(H2PO4)2:K2SO4 at 118:20:40 g plant-1; 3.75 L water plant-1] treatments. The findings of this study could be used in improving the precision and efficacy of rabbiteye blueberry planting in Guizhou, China. Such an approach can increase the productivity and profitability for local fruit farmers.
Blueberry Plants/growth & development , Blueberry Plants/physiology , Fertilizers , Water , Cluster Analysis , Photosynthesis , Plant Leaves/physiology
To assess comparative losses of Trianthema portulacastrum (HP) relative to other weeds, the experiment was set during consecutive summer seasons 2018 and 2019 at the Research Farm MNS-University of Agriculture, Multan, Pakistan. Experiment consisted three replications which were laid out under randomized complete block design. Experiment consisted of ten treatments viz: weeds free (whole season), HP free till 20 Days after emergence (DAE), HP free till 40 DAE, HP free till 60 DAE, all weeds free 20 DAE, all weeds free 40 DAE, all weeds free 60 DAE, weedy check (all weeds), weedy check except HP and weedy check containing only HP. During 2018 in all weeds weedy check, maximum HP relative density (33.33%) was observed while in 2019, plot where weeds were controlled from growing till 20 DAE showed (80%) relative density at 30 DAE. HP maximum frequency (66.67%, 77.78%) and relative frequency (66%, 100%) was recorded at 45 DAE in plots where HP was kept controlled till 20 DAE and all weeds kept controlled till 20 DAE, respectively. Maximum number of grains per cob (738, 700.68), 1000 grain weight (306.66, 271.51 g) and grain yield (6150, 8015 kg hec-1) were recorded in plots which were kept all weed free till 60 DAE. As the competition period of weeds increased over 40 DAE, it substantially reduced yield of maize. Keeping the plots HP free till 40 DAE in the maize fields with HP as the major dominating weed, likely increase in maize grain yield is up to 30% compared to the fields where HP left un attended throughout the growing season. However, if maize field is infested with a mix of weeds with more than one dominating weeds including HP, compared to weedy situation the whole season, 30% higher grain yield can be obtained if all weeds are kept controlled till 40 DAE. Hence it can be concluded that whether the farmers face heavy HP infestation only or the mix of weeds as dominating weeds, in either case farmer should control weeds within first 40 days in maize field for better grain yield.
Soil salinity disrupts the physiological and biochemical processes of crop plants and ultimately leads to compromising future food security. Sodium nitroprusside (SNP), a contributor to nitric oxide (NO), holds the potential to alleviate abiotic stress effects and boost tolerance in plants, whereas less information is available on its role in salt-stressed lentils. We examined the effect of exogenously applied SNP on salt-stressed lentil plants by monitoring plant growth and yield-related attributes, biochemistry of enzymes (superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD)) amassing of leaf malondialdehyde (MDA) and hydrogen peroxide (H2O2). Salinity stress was induced by NaCl application at concentrations of 50 mM (moderate salinity) and 100 mM (severe salinity), while it was alleviated by SNP application at concentrations of 50 µM and 100 µM. Salinity stress severely inhibited the length of roots and shoots, the relative water content, and the chlorophyll content of the leaves, the number of branches, pods, seeds, seed yield, and biomass per plant. In addition, MDA, H2O2 as well as SOD, CAT, and POD activities were increased with increasing salinity levels. Plants supplemented with SNP (100 µM) showed a significant improvement in the growth- and yield-contributing parameters, especially in plants grown under moderate salinity (50 mM NaCl). Essentially, the application of 100 µM SNP remained effective to rescue lentil plants under moderate salinity by regulating plant growth and biochemical pathways. Thus, the exogenous application of SNP could be developed as a useful strategy for improving the performance of lentil plants in salinity-prone environments.
Lens Plant/drug effects , Lens Plant/physiology , Nitroprusside/pharmacology , Plant Development/drug effects , Salt Stress/drug effects , Antioxidants/metabolism , Hydrogen Peroxide/metabolism , Lens Plant/chemistry , Plant Leaves/chemistry , Plant Leaves/drug effects , Plant Leaves/metabolism , Reactive Oxygen Species/metabolism , Stress, Physiological/drug effects
Hexokinase (HK) is a key enzyme in chitin biosynthesis in insects and plays an important role in development and energy regulation. It also performs a crucial role in the synthesis of Glucose-6-phosphate and its putative functions are studied via injection of dsRNA corresponding to the hexokinase gene from Cnaphalocrocis medinalis (CmHK). This study was designed to analyze the characteristics and expression patterns of HK-related genes in various tissues of C. medinalis at different developmental stages. The CmHK ORF is a 1359 bp in length, encoding a protein of 452 amino acids, with homology and cluster analysis showing that CmHK shares an 85.11% sequence similarity with hexokinase from Ostrinia furnacalis.CmHK was highly expressed in the ovary and in the fifth instar larvae. Injection of dsCmHK significantly suppressed mRNA expression (73.6%) 120 h post-dsRNA injection as compared to a control group. The results demonstrated an increased incidence of larval and pupal mortality of 80% and 78%, respectively, with significant variation in the sex ratio between males (68.33%) and females (35%), overt larval deformities, and a reduction in average weight gain observed 120 h post-dsRNA injection. In addition, dsCmHK-injected C. medinalis showed a significant reduction in ovulation per female and larval hatching rate, along with increased larval and pupal mortality and variation in male and female emergence over three generations (G1, G2, and G3). Taken together, the outcomes of the study provide a foundation to study gene function and a new dimension to control C. medinalis by transgenic RNAi technology.
Hexokinase/genetics , Insect Proteins/metabolism , Larva/metabolism , Moths/genetics , Amino Acid Sequence , Animals , Base Sequence , Chitin/biosynthesis , Female , Gene Expression/genetics , Larva/growth & development , Male , Ovary/metabolism , Pupa/metabolism , RNA Interference , Sequence Analysis, DNA , Sex Ratio , Testis/metabolism
Boron (B) is required during all growth stages of cotton crop, especially during boll formation. However, Typic Haplocambid soils of cotton growing belt in Pakistan are B-deficient, which results in low yield and economic returns. Foliar application of B improves cotton productivity; however, information is limited on the role of soil applied B in improving cotton growth and yield. The current study investigated the role of soil applied B in improving growth, yield and fiber quality of cotton crop. Five different B doses (i.e., 0.00, 2.60, 5.52, 7.78 and 10.04 mg kg-1 of soil) and two cotton cultivars (i.e., CIM-600 and CIM-616) were included in the study. Soil applied B (2.60 mg kg-1) significantly improved growth, yield, physiological parameters and fiber quality, while 10.04 mg kg-1 application improved B distribution in roots, seeds, leaves and stalks. Significant improvement was noted in plant height (12%), leaf area (3%), number of bolls (48%), boll size (59%), boll weight (52%), seed cotton yield (52%), photosynthesis (50%), transpiration rate (10%), stomatal conductance (37%) and water use efficiency (44%) of CIM-600 with 2.60 mg kg-1 compared to control treatment of CIM-616. Similarly, B accumulation in roots, seeds, leaves and stalk of CIM-600 was improved by 76, 41, 86 and 70%, respectively compared to control treatment. The application of 2.60 mg kg-1 significantly improved ginning out turn (6%), staple length (3.5%), fiber fineness (17%) and fiber strength (5%) than no B application. The results indicated that cultivar CIM-600 had higher ginning out turn (1.5%), staple length (5.4%), fiber fineness (15.5%) and fiber strength (1.8%) than CIM-616. In crux, 2.60 mg kg-1 soil B application improved growth, yield, physiological and fiber quality traits of cotton cultivar CIM-600. Therefore, cultivar CIM-600 and 2.60 mg kg-1 soil B application is recommended for higher yield and productivity.
Boron/metabolism , Gossypium/growth & development , Gossypium/metabolism , Biomass , Cotton Fiber/analysis , Fertilizers , Pakistan , Photosynthesis , Plant Leaves/chemistry , Plant Roots/chemistry , Seeds/chemistry , Soil/chemistry , Water
Biosolids can be effectively recycled and applied as soil amendments for agricultural crops because they contain several important micro and macronutrients including nitrogen, phosphorus, potassium, manganese. In the current study, we evaluated the effectiveness of seven biosoilds on different growth parameters of wheat crop. The biosolids used were lime stabilized, composted, liquid mesophilic anaerobically digested (liquid MAD), thermally dried mesophilic anaerobically digested (thermally dried MAD), thermally hydrolyzed mesophilic anaerobically digested (thermally hydrolysed MAD), dewatered mesophilic anaerobically digested (dewatered MAD) and thermally dried raw biosolids. We also analysed biosolids for their nutrient contents before application. The results revealed that different types of biosolids differed in nitrogen and phosphorous contents with highest contents observed in dewatered (5.70% nitrogen, 2.32% phosphorous) and liquid biosolids (2.35% phosphorous). The plant height, plant diameter and dry weight yield of wheat was increased with the increase in concentrations of biosolids. Liquid MAD resulted in maximum plant height of 120.35⯱â¯3.23, 133.2⯱â¯3.67 and 147.25⯱â¯3.11 at 3.33, 6.66 and 9.99â¯tons/ha concentration. The highest plant diameter was recorded (1.05-1.45â¯cm) where mineral nitrogen was applied. The study will be helpful in replacing the synthetic fertilizer with biosolids to fulfil the nutritional requirements of agricultural crops.
