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Suppressive effect of Pseudomonas putida BP25 emitted or synthetic volatile, 2-ethyl-5-methylpyrazine, on anthracnose disease on mango, and volatile mediated fruit quality enhancement. [Display omitted] • Native volatile of Pseudomonas putida BP25 inhibited Colletotrichum gloeosporioides. • Fumigation by native volatile or 2-ethyl-5-methylpyrazine suppressed anthracnose. • Native volatile or 2-ethyl-5-methylpyrazine enhanced nutritional quality of mango. Anthracnose disease incited by Colletotrichum gloeosporioides reduces the yield and market-quality of mangoes worldwide. Previous studies have indicated the potential of diverse antimicrobial volatile organic compounds emitted by the endophytic Pseudomonas putida BP25 for plant disease suppression. In the present study, we have explored native-volatiles of Pseudomonas putida BP25 and a synthetic-volatile, 2-ethyl-5-methylpyrazine, earlier identified in volatilome of Pseudomonas putida BP25 for reducing anthracnose in mango cultivar, Amrapali. The bacterial volatile compounds displayed fungistatic effects on the mycelial growth of Colletotrichum gloeosporioides in vitro. In planta prophylactic fumigation of mangoes with native-volatiles or the bacterial origin synthetic 2-ethyl-5-methylpyrazine for 24 h at 25 °C showed a reduction of anthracnose severity (>76 % reduction over mock) on fruit. Additionally, physicochemical qualities such as total-soluble solids, total-phenols, total-proline, total-carotenoid, total-flavonoid, and fruit-firmness were increased in fumigated fruit as compared to untreated mangoes. Anthracnose suppression coupled with the fruit quality enhancement by bacterial volatiles and synthetic 2-ethyl-5-methylpyrazine presents a new opportunity for postharvest management of mango during the storage, transit, and trade. [ABSTRACT FROM AUTHOR]

• Indicators identified for assessing maize genotypes response under elevated temperature and carbon dioxide concentration [CO 2 ]. • Crop Health Index (CHI) formulated for maize genotypes response under elevated temperature and [CO 2 ]. • Stress tolerant and susceptible maize genotype exhibited high and low CHI respectively. • CHI value indicated more tolerance to elevated temperature and [CO 2 ] in PEHM 5 as compared to CM 119. Reports on the adverse impacts of climate change on growth and productivity of crops due to elevated temperature and carbon dioxide concentration ([CO 2 ]) is persistently raising the need for development of tools to assess response of crops to climate change factors. In the present study, Crop Health Index (CHI) was generated for response of maize genotypes under elevated temperature and [CO 2 ]. Under field condition, in open top chambers PEHM 5 and CM 119 maize genotypes throughout their crop growth period were treated with two [CO 2 ] levels: ambient (400 ppm) and elevated (550 ± 20 ppm) and three temperature levels: ambient, ambient +1.5 °C and ambient +3 °C. Response of maize genotypes to temperature and [CO2] was monitored through thirteen stress indicator parameters – morphological, physiological and biochemical at three growth stages – vegetative, tasselling and dent. Yield for both genotypes under each treatment was recorded at maturity. The data was used to delineate minimum dataset (MDS) responsive to combinations of temperature and [CO 2 ] treatments through principal component analysis (PCA). Out of thirteen indicators, total dry biomass, total phenol content, relative leaf water content and photosynthetic rate was found to be having higher frequencies for MDS at all three stages. Parameters selected under MDS were transformed to get linear score (Si) using a linear scoring method and weighing factor (Wf) value. Then, average linear score (S i ¯) [(Si)] and average weightage score (W i ¯) were used to generate CHI. Results indicated that CHI for maize genotypes under different treatments varied between 0.14–0.93. Average CHI under different treatment was significantly related with yield of PEHM 5 and CM 119 and R2 was 0.82 and 0.90, respectively. It was observed that increase in temperature had detrimental effect on CM 119 and PEHM 5 genotypes with minimum average CHI of 0.20 and 0.53, respectively. On the contrary, elevated [CO 2 ] was found to be having amelioration effect on CM 119 and PEHM 5 genotypes to adverse effect of elevated temperature with highest average CHI of 0.46 and 0.75, respectively. [ABSTRACT FROM AUTHOR]

In the present study, effect of elevated temperature and CO 2 levels was assessed on maydis leaf blight (MLB) disease tolerance attributes of two maize genotypes PEHM 5 (moderately resistant) and CM 119 (highly susceptible). The maize genotypes were exposed to two CO 2 levels: ambient (400 ppm) and elevated (550 ± 20 ppm) and three temperature levels: ambient, 1.5 °C higher than ambient and 3 °C higher than ambient temperature throughout crop growth periods. Disease severity in CM 119 was higher than PEHM 5 in all treatments. The disease severity increased when temperature was increased 3 °C higher than ambient temperature, but effect of temperature was subsided when CO 2 concentration was increased from ambient to 550 ppm level. Maximum (76.5% and 95.4%) and minimum (61.7% and 78.7%) disease severity in PEHM 5 and CM 119 was observed in 3 °C elevated temperature and ambient CO 2 level; and ambient temperature and elevated CO 2 level, respectively. Six disease stress tolerance attributes were calculated based on yield under diseased (Ys) and without disease condition (Yp). Both Ys and Yp were positively correlated with disease stress tolerance index (DSTI), mean productivity (MP) and geometric mean productivity (GMP) and negatively correlated with disease tolerance (TOL) and disease stress susceptibility index (DSSI). Results showed that with the increase in ambient temperature, severity of MLB disease is likely to increase in future. [ABSTRACT FROM AUTHOR]

• Additive effect of thyme and betel leaf oil for C. gloeosporioides inhibition. • PVA nanofibres had oil loading capacity upto 75.88 %. • Developed nanofibres showed inhibition zone upto 24 cm in vitro. • Packing inoculated sapota with nanofibres reduced disease severity to 6.7 %. Control of anthracnose disease caused by Colletotrichum gloeosporioides by use of essential oils encapsulated in nanofibres made of polyvinyl alcohol has been attempted in this study. Essential oils from plants of subtropical origin, thyme oil and betel leaf oil were incorporated in electrospun mats at different levels. The Scanning Electron Microscope analysis revealed size of the nanofibers between 180 and 302 nm. Effective Dose (ED 50) values for the pure oils and their blends (1:3; 1:1; 3:1) ranged from 77 to 148 ppm. The blended essential oils demonstrated additive effect for inhibition of the pathogen with Abbott index >0.5. Oil loading capacity, determined using Gas Chromatography Electron Capture Detector ranged from 40.15–75.88% and was found proportional to feed content. No major effect of incorporation of thyme oil and betel oil on polymeric structure was observed in Fourier-transform infrared spectra. A Band near 876cm−1 and 1250 cm−1 signified the presence of both thyme and betel oil respectively. The composite nanofibers with blended oils at three levels showed inhibition zone from 6.6 mm to 11.6 mm on 3rdday of incubation, which increased further upto 24 mm on the 6th day. Sapota fruits inoculated with Colletotrichum gloeosporioides recorded disease severity of 83.33 %, 8.39 % and 6.72 % when packed in corrugated fiber board boxes with composite nanofibers as compared to control fruits (100 %) on the 6th day of incubation at 28 °C. Burning symptoms on skin were observed on fruits kept in contact with same level of essential oil infused sterile cotton balls highlighting the importance of encapsulated oils for disease control. [ABSTRACT FROM AUTHOR]