Avirulence gene based RFLP and rep-PCR distinguish the genetic variation of Xanthomonas oryzae pv. oryzae pathotypes in Bangladesh

Bacterial blight (BB) caused by X. oryzae pv. oryzae is one of the devastating diseases of rice mostly in Asia. Genomes of X. oryzae pv. oryzae is highly variable due to rearrangement of the large contents of transposable elements and dynamic changes of X. oryzae pv. oryzae population regulated efficiency of the control measures used for BB management of rice worldwide. In this study, genetic variation of X. oryzae pv. oryzae pathotypes of Bangladesh was studied using aviruelnce gene based RFLP and rep-PCR techniques aimed to formulate pathogen targeted effective control measures against BB of rice. Eight pathotypes of X. oryzae pv. oryzae field isolates were identified based on their reactions against 10 Near Isogenic Lines (NILs). Among eight pathotypes, pathotypes IV and V contained higher number of isolates which were 30.13% and 23.01% respectively while pathotype VIII revealed as minimum containing only 2.51% of total isolates. These eight pathotypes were studied for their genetic variation by RFLP using avrBs3 repeat domain as probe. The results conceded that Bangladeshi X. oryzae pv. oryzae strains seem carrying a minimum of two and maximum of nine avrBs3 family genes homologs. The resistance phenotype on IRBB7 and IRBB10 NILs also indicated presence of two major avrBs3 family genes viz. avrxa7 and avrXa10 in some pathotypes. Relationship of phylogenicity exhibited that X. oryzae pv. oryzae pathotypes assorted into two RFLP haplotypes as well as these haplotypes are largely distributed in Bangladesh. Phylogenetic analyses carried out by (REP, ERIC), rep-PCR and BOX depicted the presence of two main molecular haplotypes of X. oryzae pv. oryzae pathotypes. The relationship between pathotypes and molecular haplotypes of X. oryzae pv. oryzae in Bangladesh indicated that the same lineage possesses different pathotypes and different lineage possesses different pathotypes. The results indicated that eight different pathotypes might have originated from common inherited haplotypes with a wide genetic variation.

Spectral analyses of fresh and dry Hypericum perforatum L. Effects with colloidal nano silver 30 ppm

Spectral analyses of 1% water extracts of fresh and dry Hypericum perforatum L. and 1% dry H. perforatum with colloidal nano silver (NSPs) 30 ppm were conducted. The nano silver is standardised and patented by the Swiss company Evodrop. Non-equliblrium energy spectrum (NES) and Differential non-equliblrium energy spectrum (DNES) methods were used for the spectral analysis. A comparative analysis of 1% extracts of fresh and dry H. perforatum was performed in order to determine the local extremums for effects of nerve tissue conductivity at (-0.1112) eV, anti-inflammatory (-0.1212) eV, anti-tumor effects (-0.1387) eV. The results showed stimulating effect on the nervous system and improvement of nerve conduction (local extremums E=-0.1112 eV)(?=11.15 ?m) (?=897 cm-1), as well as anti-inflammatory effect (E = -0.1212 eV)( ?=10.23 ?m) (?=978 cm-1) and inhibition of development of tumor cells at a molecular level (E=-0.1387 eV) (?=8.95 ?m) (?=1117 cm-1). It was found that clusters of 16 and 15 water molecules are formed in the water herbal extracts of fresh H. perforatum and of dry H. perforatum with AgNPs 30 ppm. The fresh plant showed better results then the dry one. The addition of colloidal nano silver 30 ppm led to better results of the drug.

Osmolyte-induced water deficit stress mitigation during panicle initiation stage in transplanted rice (Oryza sativa L.)

A field experiment was conducted to observe the osmolyte-induced water deficit stress mitigation during the panicle initiation stage in transplanted rice (Oryza sativa L. cv. BRRI dhan72). At the panicle initiation stage, plants were simulated with four levels of water regimes viz., well-irrigated (D0), water deficit for 5 d (D1), 10 d (D2) and 15 d (D3). Plants were treated with or without 10 mM of proline (Pro) and trehalose (Tre) as foliar spray started at mid-vegetative stage and continued till the end of stress period. Results revealed that water deficit stress drastically reduced most of the plant morpho-physiological attributes while other yield contributing characters were also affected due to prolonged water deficit stress. However, exogenous application of osmolytes like Pro and Tre significantly increased all those morphological, physiological and yield contributing parameters. Foliar addition of osmolytes concomitantly decreased the number of non-effective tillers hill-1 and the number of unfilled grain panicle-1 under water stress condition. Although both the osmolytes performed well under multiple duration of drought stress, the application of 10 mM Pro markedly improved all growth and yield contributing parameters under D1 water deficit stress compared to other stress durations. Hence, it may be concluded that the use of osmolytes would be a prospective remedy against moderate water deficit stress in transplanted rice production.

Effect of irrigation levels and foliar application of fertilizers on some agronomic and oil characteristics of castor bean (Ricinus communis L.)

To study the effect of irrigation levels and foliar application of fertilizers on some agronomic and oil characteristics of castor bean, an experiment was conducted at the East Azarbaijan Agricultural Research and Education Center, Tabriz, Iran in 2017-2019 cropping seasons. The experiment was laid out as a split-plot design based on a completely randomized block design with three replications. In the present study, main cluster length, number of branches, number of capsules per plant, number of seeds per capsule, 100-grain weight biological yield, grain yield, oil percent and oil yield were measured. Irrigation intervals (normal irrigation (irrigation after 60 mm), irrigation after 80 mm and 140 mm of evaporation) was established as main plots and the foliar applications of fertilizers (N, K, S, N + K, and N + S, K + S, N + K + S and control) input as sub-plots. The results showed that, except for the oil percentage, all the examined traits were decreased by water limitation. The highest values of the traits, other than the 100-grain weight, were obtained for foliar application of N + K + S. This treatment improved the grain yield per unit area under normal irrigation and moderate irrigation and severe stresses by 62.76%, 41.46% and 28.98% respectively. Thus, the foliar application of S (2000 ppm) + N (3000 ppm) + K (3000 ppm) fertilizer is the best treatment for mitigating some harmful effects of water deficit on castor bean.

Growth and yield assessment of lettuce (Lactuca sativa L.): an economic feasibility and performance evaluation of capillary wick irrigation system

The study assessed the growth and yield of lettuce (Lactuca sativa L.) in order to evaluate the performance and economic feasibility of capillary wick irrigation system. Unlike any other capillary rise-based systems that uses the matric potential of the soil to dictate the amount of water to be drawn, this system aimed to continuously supply water imitating a full-time drip irrigation system but cheaper in terms of materials and operating cost. A 5 mm-width, cotton fabric strip was used as a wick material based from the results of the preliminary testing to verify several literature claims. In order to determine number of wicks to optimally supply the water demand of lettuce, treatments namely, T1= 1 wick, T2 = 2 wicks, T3 = 3 wicks and a control treatment T4 which uses manual irrigation method, were tested and compared against each other. Significant results were in terms of the volume of water applied, and the water use efficiency in which T1 showed a better performance among other treatments. However, it does not imply that T1 had produced a supreme yield output. Instead, this can be attributed to the efficient application of irrigation water to an optimal level. This means that T1 or the use of 1 wick material minimizes irrigation water losses through evaporation and percolation. An economic analysis was performed and has resulted to a return on investment of 41.92% or 41.92% of the investment cost will be returned after three cropping, which is an attribute of the particular set-up cost of the study.

Rosmarinic acid production in cell suspension cultures of Ehretia asperula Zollinger & Moritz

Plant cell cultures provide an alternative means for producing secondary compounds in food, cosmetic and pharmaceutical industries. Ehretia asperula Zollinger & Moritzi is used as a traditional medicine for the treatment of liver detoxification, ulcers, tumors, inflammation and enhancing the body's resistance in Vietnam. The study was carried out to select suitable callus line for cell suspension cultures of E. asperula Zollinger & Moritzi and investigate the effects of inoculum size, rotation speed and naphthalene acetic acid (NAA) on the proliferation of cell suspension cultures. In addition, the influence of light intensity on the growth and rosmarinic acid (RA) biosynthesis of cell suspension was also surveyed. After 4 weeks of culture, the white to pale yellow friable callus expanded significantly with a fresh weight (FW) of 0.788 g and a high RA content of 2.062 mg/g FW. An appropriate medium for cell proliferation was the liquid B5 medium, which contained 30 g/l glucose, 0.1 mg/l benzyl adenine (BA) and 0.4 mg/l NAA. The results also demonstrated that a 1:20 ratio (w/v) inoculum size, darkness and rotation speed of 90 rpm were the optimal conditions for the proliferation and RA accumulation to 188.217 mg/l in 4 weeks of culture. These findings showed that E. asperula Zollinger & Moritzi cell suspension cultures could be a potential alternative approach for RA production in vitro.

Quality attributes of cantaloupe (Cucumis melo L.) fruit under pre-harvest and post-harvest treatment with methyl jasmonate and salicylic acid

Cantaloupe (Cucumis melo L.) is one of the most delicious fruits popularly cultivated in tropical regions due to its sweet-juicy taste, attractive flavor and bioactive composition. Extending cantaloupe shelf-life during handling and distribution is very necessary to upgrade its commercial value. Methyl jasmonate (MJeA) and salicylic acid (SA) are bio-regulators widely applied on either pre- or post-harvest to extend the shelf life and maintain fruit quality during storage. In this investigation, the possibility of both pre-harvest (7 days before harvesting) via spraying and post-harvest (immediately after harvesting) evaluated by dipping on cantaloupe fruit by either MJeA (3 mM) or SA (3 mM) separately; in combination with MJeA/SA (1.5/1.5 mM/mM) for 30 s. These fruits were kept at 24±0.5 oC for 28 days of storage. In 7 day-interval, fruits were sampled to verify firmness, weight loss, decay rate, total soluble solid, carotenoid, vitamin C, total phenolic content, total flavonoid content. Results revealed that there was a significant difference in quality attributes between the treated samples and the control ones. However, there was no significant difference in quality attributes on either pre-harvest or post-harvest treatments by MeJA and SA reagents. Incorporation of MJeA/SA (1.5/1.5 mM/mM) by either pre-harvest or post-harvest maintained the most firmness (52.10±0.11 N or 52.37±0.08 N), total soluble solid (18.08±0.05 oBrix or 18.15±0.04 oBrix), carotenoid (46.97±0.02 µg/100 g or 47.10±0.03 µg/100 g), vitamin C (26.04±0.02 mg/100 g or 26.17±0.02 mg/100 g), total phenolic content (117.86±0.05 mg GAE/100 g or 119.75±0.09 mg GAE/100 g), total flavonoid content (84.04±0.02 mg QE/100 g or 84.20±0.02 mg QE/100 g) as well as the least weight loss (3.74±0.01% or 3.66±0.03%) and decay rate (1.42±0.01% or 1.26±0.03%) at the end of 28 days of storage. The synergistic effect of MeJA and SA would be a promising alternative to preserve cantaloupe fruit quality with a long shelf life.

In vitro growth and content of vincristine and vinblastine of Catharanthus roseus L. hairy roots in response to precursors and elicitors

Catharanthus roseus L. is a medicinal plant that produces numerous indole terpenoid alkaloids, including vincristine and vinblastine, which are used for cancer treatment. The effect of specified precursors (L-phenylalanine, L-tyrosine) and elicitors (chitosan, methyl jasmonate) on C. roseus hairy roots (CHR) growth has been examined in order to increase the content of vincristine and vinblastine. Our results showed that CHR generated by an Agrobacterium rhizogenes strain isolated in Vietnam was capable of producing both vincristine and vinblastine when subjected to precursors, but only vinblastine when exposed to elicitors. However, both precursors and elicitors were evaluated to have an effect on increasing the accumulation of TIAs in CHR. In particular, the use of elicitors required more time to find the appropriate induction conditions, while the use of precursors gave outstanding efficiency in the treatment with 1 µM phenylalanine. The greatest yields of vincristine (51.99 µg g-1 DW) and vinblastine (699.92 µg g-1 DW) were obtained in the 7th week (with 0.306 g DW biomass). This result is the first time we might boost the levels of vincristine and vinblastine in our CHR clone generated by the Vietnam strain of A. rhizogenes.

Aposporic development of gametophyte in Sematophyllum subpinnatum (Brid.) E. Britton (Sematophyllaceae) from capsule wall

In the present study, an axenic culture of Sematophyllum subpinnatum (Brid.) E. Britton was attempted from spores. However, spores failed to germinate, but protonemata were seen arising from the diploid capsule wall cells by apospory. Few cells of the capsule wall turned green, and the protoplast divided, resulting in the extension of the protoplast as a germ tube, which developed into protonemata. Protonemata were less spreading, and adult gametophytes developed from these protonemata. The aposporic plants so developed were transferred to soil, and they showed normal growth but with decreased branching. No sex organs and sporophytes were seen. This is the first report of aposporic development of S. subpinnatum from the capsule wall.

Plant growth promotion of barley (Hordeum vulgare L.) by potassium solubilizing bacteria with multifarious plant growth promoting attributes

Potassium (K) is the foremost macronutrients for growth of plant, soil health and fertility. The huge application of NPK chemical fertilizers negatively impacts the economy and is a threat to environmental sustainability. The rapid depletion of K mineral in soil is due to the application of agrochemicals agricultural fields for the production of crops in India. In present investigation, K-solubilizing microbes (KSM) were isolated and enumerated from cereal crops growing in Sirmour Himachal Pradesh. A total 125 bacteria were isolated and screened for K- solubilization on Aleksandrov agar plates and found that 31 bacterial strains exhibited K-solubilization. These 31 K-solubilizing strains of bacteria were additionally screened for other plant growth promoting (PGP) potential including solubilization of minerals, production of siderophores, ammonia, hydrogen cyanide and indole acetic acids. The performance of an efficient K-solubilizer was evaluated for plant growth promoting ability in pot assay under in vitro conditions. The strain EU-LWNA-25 positively influenced shoot length, fresh weight, carotenoids and total sugar content than the full dose, half dose and control. The strain enhancing physiological and growth parameters was identified by BLASTn analysis as Pseudomonas gessardii EU-LWNA-25. K-solubilizing plant growth promoting bacteria could be suitable bioinoculants for Rabi seasonal crops and overcomes the challenges of sustainable agriculture in K-deficient soil.