Impacts of drought and herbicide stress on seed germination and early seedling growth in a legume crop mung bean (Vigna radiata L.)

Abiotic stress such as drought and agrochemicals leads the drastic reductions in legume yields, hence, in order to mitigate the loss of yields due to abiotic stresses, the production of stress tolerance genotypes of the legumes could be a rewarding approach. Therefore, the aim of the present study was to evaluate the drought and herbicide stress effects under ex-vitro conditions on seed germination and early seedling growth in a legume crop mung bean (Vigna radiata L.). To begin with, drought stress was induced by employing various concentrations of mannitol (50mM, 100mM, 250mM, 500mM, 750mM, and 1000mM) and polyethylene glycol (PEG-5%, 10%, 15%, 20%, and 25%) while during herbicide stress experiments, dicamba (3,6-dichloro-2-methoxybenzoic acid) and picloram (4-Amino-3,5,6-trichloro-2-pyridine carboxylic acid) were considered in various concentrations (5mg/L, 25mg/L, 50mg/L, and 100mg/L) of each. Moreover, data were collected as partial and full seed germination after 3- and 7-days of stress treatments respectively. After 7-days of mannitol stress treatments, results reveals that even the high concentration of mannitol (500mM) could be proved as weak osmotic stressor for seed germination (35%±0.14) in comparison to control (91%±0.74) while further increase in mannitol concentration (750mM) was proved to be lethal, toxic and inhibits seed germination completely. Furthermore, in comparison to mannitol, PEG turns out as strong osmotic stressors and (15%) of PEG was proved to very lethal for seed germination. Even during early seedling growth, increased concentrations of both mannitol and PEG were found to be inhibitory. Among two herbicides, the result shows that both herbicides (dicamba and picloram) were proved to be completely toxic and lethal even at very low concentrations (5mg/L) and induced abnormal seed germination and inhibited completely seedling growth. However, the inhibitory response of picloram herbicide stress on seed germination was found to be more pronounced and severe than dicamba herbicide. Hence, the present study reveals that in comparison to mannitol, PEG turns out as a strong osmotic stressor while picloram proves to be a relatively more toxic herbicide than dicamba for seed germination. Additionally, drought stress induced seedlings on transfer to soil exhibit inhibited growth under continuous irrigation with either mannitol or PEG solutions.

Evaluation of Hararge coffee (Coffea arabica L.) landraces for moisture stress tolerance

Arabica Coffee is an important export commodity for Ethiopia, contributing 25 to 30 % of the country’s total foreign exchange earnings. Moisture stress is one of the major constraints of coffee production in Hararge, Eastern Ethiopia. Moisture stress affects the growth, yield and quality of coffee. Local coffee landraces are source of desirable traits including moisture stress tolerance. Accordingly, this study was conducted to evaluate Hararge coffee landraces for moisture stress tolerance. Treatments consisted of 200 coffee landraces (178 from seven districts of east Hararge Zone and 22 from two districts of west Hararge Zone). The coffee landraces were field planted in July 2005 at Mechara Agricultural Research Center using augmented design with six trees per plot or accessions. Moisture stress tolerance was recorded from three randomly selected coffee trees per plot, three times a day (in the morning, noon and night) from January 05 to 25, 2014. The stress tolerance was determined using 1-5 scale by visual scoring (1- all leaves green and turgid, 2- most leaves still turgid but younger leaves show leaf folding; 3- all leaves wilt or fold, 4- Leaves partially turning pales, and partly shed showing severe wilting and 5-leaves completely turning brown and dry, mostly dropping). The collected data were analyzed using descriptive statistics. The result of this study revealed that the coffee landraces varied in their level of tolerance to moisture stress. The 200 coffee landraces were grouped into seven clusters based on their level of tolerance to moisture stress. Nine coffee landraces (4.5%) were highly tolerant to moisture stress, 25 (12.5%) were tolerant, and 36 (18%) were moderately tolerant. On the other hand, 60 coffee landraces (30%) were less tolerant; while 57 (28.5%), 11(5.5%) and 2 (1%) were moderately sensitive, sensitive and highly sensitive to moisture stress, in that order. There was variation in coffee landraces for moisture stress tolerance both between and within areas of the collection. Hence, it is advisable to maintain and use promising coffee landraces in coffee breeding. Screening of the landraces under controlled conditions like green house and studying of mechanisms of moisture stress is also the way forward.

Accumulation of total nutrients, dry matter and phytochrome content in Boesenbergia stenophylla R.M Smith as affected by different light conditions

A study was conducted to determine the best agronomic practices for the cultivation of jerangau merah as a new medicinal crop. Jerangau merah is scientifically known as Boesenbergia stenophylla is a ginger plants that is highly endemic to the Borneo Highland. This understorey herb grows in cluster and under the heavy shades of forest canopies and perceived only the sunflecks that pass through the forest canopies. Jerangau Merah has been consumed by the locals for its medicinal values since decades ago. Generally, B. stenophylla is well known for its function as antidote for alcohol. Moreover, the B. stenophylla is also beneficial for rheumatic pains, remedies for stomach ache and toothache and as antiseptic wash as well. This herb is not propagate by the locals due to its sensitivity to sunlight and lack of agronomic information for B. stenophylla. Harvesting it from their natural habitat, however, seen the decline it its population size hence cultivation is essential. This paper aimed to determine the total nutrients, dry matter yield and phytochrome content of Bosenbergia stenophylla R.M. Smith under different light regimes. A study for determining suitable planting media for B. stenophylla was conducted at Universiti Putra Malaysia (UPM). The treatments are: i) (M1) with the ratio of 3:2:1 top soil: sand: organic matter, media ii) (M2) consists of soil mixture 3:2:1 placed in water-logged polyethylene bags and media iii) (M3) contained only leaf litters. The results showed that the herbs showed significantly higher number of shoots and leaves in the common soil mixture. But, better root development in media containing leaf litters. The study proceeded with field experiment at Ba’Kelalan to determine the effect of different shade levels and fertilizing regimes on growth. B. stenophylla was cultivated under two different levels of shade cloths: 70% and 90% level of shade and different fertilizing regimes (T1 as control, no fertilizer applied to the plants; T2, chicken dung; T3, NPKMg and T4, mixed of chicken dung and NPKMg). The study for determining the effects of different shade level and fertilizing regimes on seedling’s growth which conducted at Ba’Kelalan in factorial randomized completely blocked design (RCBD). The data collected for 9 weeks of planting which include nutrient content in soil, leaf, PAR and phytochrome content and growth parameters. Regarding the nutrient uptake, the results showed no interactions between fertilizing regimes and shade levels. There were no significant different in nutrient elements except for magnesium and potassium. Magnesium is essential for the formation of chlorophyll which ensure efficiency of photosynthesis when under higher light intensity. Among all the fertilizer treatment, it was showed that chicken dung amendment has higher nutrient uptake. Thus, it is recommended chicken dung should be added into the NPKMg for better nutrient uptake. Further study on suitable fertilizer rates apply to B. stenophylla should be taken into consideration. Moreover, plants cultivated under 70% have been higher and have higher dry matter yield than those plants cultivated under 90%. The result also revealed that there was significant different in chlorophyll content of B. stenophylla cultivated under 70% which treated either with chicken dung and NPKMG respectively. However, plants under 90% have higher chlorophyll content than those under 70%. Based on the results, plants under 70% shade was taller than those under 90% and there were significant difference in height among treatments under 70%. It was observed plant treated with NPKMg was taller. This study showed that shade and fertilizers significantly affected the dry matter yield of B. stenophylla. Moreover, adding NPKMg to the treatments yields more dry matter content of jerangau merah. As for phytochrome content, there was no significant effect of fertilizer on phytochrome content. However, there was significant difference among the shade levels. 90% shade showed higher phytochrome content than those under 70%. In overall, both shade and fertilizer is important in cultivation of Jerangau Merah. 70% shade was observed to have significant effects on growth of jerangau merah and also more economical compared to 90%. Moreover, combination of organic matter and NPKMg also promote the growth of jerangau merah enhance the nutrient uptake efficiency of jerangau merah. However, further investigation of suitable fertilizer and application rate are required to determine suitable fertilizer for jerangau merah and application rate for optimum growth of jerangau merah.

Growth performance and nutritional quality of selected vegetables in response to organic and inorganic fertilizers under low and high irradiance

Vegetables form major part of human dietary/nutritional needs. It provides the necessary vitamins and minerals as well as antioxidants to boost immunity. Different vegetables however have different benefits and require different growing conditions. This study investigated the effect of two growing conditions (Screen-house and open field) and soil amendments; Mexican sunflower compost (MSC; applied at 0, 5, 10 t/ha) and NPK 15:15:15 (applied at 0, 50 and 100 kg N/ha) on the growth performance, yield, and nutritional quality of five selected vegetables (Amaranthus cruentus, Celosia. argentea, Solanum macrocarpon, Solanum nigrum and Solanum incanum). Each treatment was replicated three times and experiment arranged in completely randomized design, Compost was applied a week before seed sowing vegetables grown in the screen-house generally performed better than the open field in terms of leaf area and chlorophyll content. The response however varied based on the vegetable and the soil amendments. Solanum species, performed better than Amaranthus under screen-house than open field. Chlorophyll in the leaf responded positively to NPK fertilizer under screen-house conditions while growth parameters such as plant height, stem girth, number of leaves under screen-house and field conditions varied depending on the vegetables. The number of leaves and leaf area increased with soil amendments. Moisture, crude protein and ash contents were reduced under open field compared to screen-house. The zinc and iron contents of the vegetable leaves showed that addition of compost was superior to NPK and screen-house better than open field. It can be concluded that vegetables grown in the screen-house performed better in their respective growth parameters than vegetables are grown under the open field.

The Growth, productivity and nutritional status of Salicornia brachiata Roxb. cultivated in saline soils supplemented with organic manures under sea water irrigation

Halophytic crops are being explored for their nutritional, culinary, oilseed, forage/ feed crop, medicinal, and wastewater treatment potential. Along the Palk Bay region, a short term field experiment was conducted at coastal inlands of Kattumavadi village of Puthukottai district, Tamilnadu during the monsoon season of 2017 to evaluate the cultivation potential of Salicornia brachiata Roxb. in coastal sandy loam soil supplemented with different rates of farmyard manure (FYM) and halophytic compost (HC) irrigated with seawater. Observations recorded in the present study clearly indicated that supplemental fertilizers can play a vital role in the restoration of soil fertility, particularly in terms of available nitrogen and organic carbon in saline soils. HC treated plants showed increased biomass production (3240 Kg ha-1) at 60 DAP compared to control and other treatments. The application of FYM @ 2 ton ha-1 and HC @ 1 ton ha-1 significantly enhanced dry matter production and the proximate analysis exhibited less variation in total phenols and ascorbic acid with the increase in the rates of manure applications.

Salinity endurance of marine macro Rhodophycean algae with special emphasis on myo-inositol biosynthesis: An enzymological analysis from Halymenia venusta Børgesen

Altered salinity is one the most important perils encountered by marine plants inclusive of algae. Under hyper saline condition plants accumulate several stress relieving osmolytes including myo-inositol, the most widespread cyclitol in plants. The present communication reports the occurrence of myo-inositol biosynthesis in six different Rhodophycean seaweeds growing under stressful intertidal habitats of the Okha coast (Gujarat, India), on the basis of a study conducted on two marker enzymes of myo-inositol biosysnthesis [L-myo-inositol-1-phosphate synthase and D/L-myo-inositol-1-phosphate phosphatise]. Both enzymes were partially purified from Halymenia venusta to about 27 and 39 folds respectively over the homogenate following low-speed centrifugation, 30-75% ammonium sulphate fractionation, successive chromatography through DEAE-cellulose / CM-Cellulose, Sephadex G-200 and BioGel 0.5m / UltrogelAcA 34 columns. The temperature and pH optima for both the enzymes were similar and were recorded to be 350C and 7.5 respectively. For MIPS, D-glucose-6-phosphate and NAD were the exclusive substrate and coenzyme respectively and D/L-MIP was the sole substrate for MIPP. The Km values for D-glucsoe-6-phosphate and β-NAD were recorded to be 3.599 mM and 0.2366 mM respectively, while the Km value for D-MIP was found to be 0.4070 mM. Monovalent cations K+ had slight stimulatory, Li+ was strong inhibitory for both the enzymes. Divalent cations Ca2+ exhibited slight stimulatory and Cd2+ reduced MIPS and MIPP activities. MIPP was stimulated by Mg2+. Cu2+ and Hg2+ were strong inhibitors of both the enzymes. A steady and proportionate increase in the content of free myo-inositol was observed along with elevated levels of recorded salinity.

Fatty acid desaturases modulated octadecanoid pathway in Sesame

Omega 3 fatty acid desaturases are involved in the production of α-linolenic acid (LNA) an essential omega 3 fatty acid, which is present in only traces in sesame seeds. LNA is the precursor for jasmonic acid which is the end product of octadecanoid pathway. This study was undertaken to analyze the key components of octadecanoid pathway and its relationship with fatty acid content in sesame. Fatty acid desaturation and membrane fluidity are modulated differentially in various stresses. Sesame seedlings were subjected to transient stress to analyse the octadecanoid pathway and its impact on fatty acid desaturation. The mRNA levels of omega 3 desaturases and LNA content were higher in cold stressed sesame seedlings than heat, drought and salinity stresses. The LOX activity and MDA content were higher in heat stressed sesame seedlings. Jasmonic acid content was higher in salinity stressed seedlings while abscisic acid registered the highest in drought stressed seedlings. Chloroplast fatty acid desaturase genes expression was found to increase the LNA content in cold stressed seedlings. The level of membrane damage measured by lipid peroxidation in terms of LOX activity and MDA content were found to be minimal in cold stressed seedling. This suggests a possible role of LNA in membrane fluidity and cold acclimation in sesame. A synergistic role of JA and ABA is also suspected in abiotic stress tolerance in sesame.

Attempt of Costus arbuscular mycorrhizal inoculants association with leguminous foliage whey on chlorophyll of sunflower (Helianthus annus L.) plants

Reporters founded that mycorrhizal association in plant kingdom improves the plant growth. The present attempt has been on the use of Mycorrhiza for Helianthus growth in stress condition of the adverse red soil of konkan region, India and other climatic factors. Earlier reporters for the purpose to avoid chemical fertilisers, founded that Deproteinised juice (DPJ) or foliage whey induces appropriate plant growth and enhance soil fertility. During present investigation, mycorrhiza from Costus sp application to soil of potted sunflower plants influence was compared with organic DPJ addition obtained from fenugreek foliage during the process of green crop fractionation (GCF) technique. This whey is randomly disposed during this technology of leaf protein preparation, so appropriate use of it is advised. Whether the mycorrhiza and DPJ combination treatment were feasible for seed germination and the seedling growth of the Helianthus plant, it was analysed and compared with control. Studies were experimented on the effect of mycorrhiza treated alone and DPJ treated alone whether improves the plant growth. DPJ if added with mycorrhiza in soil, showed significant rate of germination. In earlier research, it was elucidated that the DPJ contains phytohormones auxins, gibberellins and cytokinins in unknown quantity which boosts the plant growth comparative to mycorrhizal influence. The chlorophyll content of the DPJ treated plants enhanced as compared with control while the content showed no significant difference with mycorrhiza.

Screening and Biochemical Characterization of Wheat Cultivars Resistance to Magnaporthe oryzae pv Triticum (MoT)

Global food security is seriously threatened due to increased frequency and occurrence of fungal diseases. One example is wheat blast caused by Magnaporthe oryzae is a fungal diseases of rice, wheat, and other grasses, that can destroy the whole food production to sustain millions of people. Wheat blast was first detected in february 2016 with a serious outbreak in Asia. Assessment of the available germplasms to stress tolerant/resistant is one of the best options for developing stress tolerant crop varieties. In this study, a total of sixteen wheat cultivars were collected and test their disease severity to blast pathogen Magnaporthe oryzae pv. Triticum (MoT). Among the varieties, BARI Gom 33 exhibited partially resistance against blast pathogen, whereas all other genotypes become susceptible to MoT. Different yield and yield contributing characters of both resistant and susceptible cultivars were also evaluated and found no significant differences among them. To understand the underlying mechanism of resistance in BARI Gom 33, antioxidant enzyme activity, concentration of reactive oxygen species and cellular damage after fungal infection were also evaluated and found that activities of ascorbate peroxidase (APX), catalase (CAT) and peroxidase (POD) were higher in BARI Gom 33 than BARI Gom 25 and BARI Gom 31. The hydrogen peroxide (H2O2) and malondealdehyde (MDA) content in BARI Gom 33 was low compare to BARI Gom 25 and BARI Gom 31, which may due to greater increase of the APX, CAT and POD in resistant genotypes. Thus, it may suggest that a more efficient antioxidative defense system in BARI Gom 33 during the infection process of M. oryzae restricts the cell damage caused by the fungus. The identified genotypes can either be used directly in the blast prone area or as a source of resistance to further development of blast resistance high yielding wheat variety.

Phenotyping of mungbean (Vigna radiata L.) genotypes against salt stress and assessment of variability for yield and yield attributing traits

Salt tolerance is a complex polygenic trait that is genotype specific and tolerance can depend upon a plants developmental stage. To evaluate reproductive stage specific salt tolerance as well as investigate the inherent variability of mungbean (Vigna radiata L.) genotypes with respect to seed yields and yield-related traits, a pot culture experiment was conducted using 26 mungbean genotypes and exposure to salt stress (EC = 8.0 dS/m) applied at the reproductive stage, just before the opening of the first flowers. The experiment involved maintaining 100% field capacity for three weeks and used a randomized complete block design with three replicates. Data were collected, included days to maturity, plant height (cm), number of pod-bearing branches per plant, number of pods per plant, pod length (cm), number of seeds per pod, 100-seed weight (g) and seed yield per plant (g). Salt stress led to a significant (p<0.001) decrease in seed yield per plant, with yields of the genotypes BMX 11116, BMX 11176, BMX 11140, BMX 11111 and BMX 11163 being the least impacted by exposure to salt. Principal component analysis revealed that the first two components explained 63.5% of the total variation among the mungbean genotypes. Seed yield per plant showed a significant positive correlation with days to maturity, number of pod-bearing branches per plant, number of pods per plant, pod length (cm), number of seeds per pod, and 100-seed weight (g). Cluster analysis grouped the 26 genotypes into five distinct clusters, where the tolerant genotypes placed in cluster I. Based on their stress tolerance indices BARI Mung-6, BMX 11176, BMX 11116, and BMX 11140 were categorized as tolerant genotypes, were selected for further study under direct field conditions and are recommended for the genetic improvement of salt stress tolerance in mungbean.