Influence of meteorological parameters on wheat yield under different sowing conditions

Field experiments were conducted on the research farm of IARI, New Delhi during Rabi 2016-17 and 2017-18. Three varieties of wheat (PBW-723, HD-2967 and HD-3086) were sown on three different dates for generating different weather condition during various phenological stages of crop. Results showed that during early crop growth stages soil moisture had higher value and soil temperature had lower value and with progress of crop growth stage, the moisture in the upper layer decreased and soil temperature increased significantly as compared to the bottom layers. During tillering and jointing stage, air temperature within canopy was more and relative humidity was less while during flowering and grain filling stage, air temperature within canopy was less and relative humidity was more in timely sown crop as compared to late and very late sown crop. Radiation use efficiency and relative leaf water content had significantly higher value while leaf water potential had lower value in timely sown crop followed by late and very late sown crop. Yield had higher value in HD-3086 followed by HD-2967 and PBW-723 in all weather conditions. Canopy air temperature difference had positive value in very late sown crop particularly during flowering and grain-filling stages. This reflects in the yield. Yield was more in timely sown crop as compared to late and very late sown crop.

Increasing photosynthetic productivity of cereal bioenergy crops as affected by the water content in leaves under mycorrhization of the root system

Purpose. To determine photosynthetic productivity of miscanthus gigantheus and switchgrass as affected by leaf water content under mycorrhization of their roots. Methods. Field, laboratory, and statistical. Results. The obtained results indicate that the use of vesicular-arbuscular mycorrhizal (VAM) preparations Mycofriend (fungus Trichoderma harzianum RIFAI.), Mikovital (fungus Tuber melanosporum VITTAD.), and nitrogen-fixing preparation Florobacillin (Bacillus subtilis Cohn.) helps to increase water content in the leaves of such cereal bioenergy crops as miscanthus gigantheus and switchgrass. In particular, in all vegetation periods, in the treatments with Mycofriend, the water content in miscanthus gigantheus leaves was higher by 11.2–20.1% than in the control, while in switchgrass it was higher by 16.9–20.5% than in the control. In the treatments with Mikovital and Florobacillin, leaf water content ranged in miscanthus from 7.1 to 15.6% and from 5.8 to 11.7%, respectively, and in switchgrass, from 11.6 to 14.7% and from 7.0 to 10.2%, respectively. The photosynthetic productivity of these crops is affected by the water content in the leaves. There is a close correlation between these factors (correlation coefficient 0.95–0.96). Conclusions. Root application of biological plant products Mycofriend, Mikovital and Florobacillin improves water content in the leaves of cereal bioenergy crops, such as miscanthus gigantheus and switchgrass, and increases their photosynthetic productivity.

A method to experimentally clamp leaf water content to defined values to assess its effects on apoplastic pH

Background Leaf hydration is controlled by feedback mechanisms, e.g. stomatal responses, adjustments of osmotic potential and hydraulic conductivity. Leaf water content thus is an input into related feedback-loops controlling the balance of water uptake and loss. Apoplastic alkalisation upon leaf dehydration is hypothesized to be involved in water stress related signaling on tissue level. When studying these mechanisms and their intermediate signaling steps, an experimenter has only poor means to actually control the central experimental variable, leaf water content (LWC), because it is not only dependent on external variables (e.g. air humidity), which are under experimental control, but is also governed by the biological influences controlling transpiration and water uptake. Those are often unknown in their magnitude, unpredictable and fluctuating throughout an experiment and will prevent true repetitions of an experiment. The goal of the method presented here is to experimentally control and manipulate leaf water content (LWC) of attached intact leaves enclosed in a cuvette. Results An experimental setup was developed where LWC is measured by a sensor based on IR-transmission and its signal processed to control a pump which circulates air from the cuvette through a cold trap. Hereby a feedback-loop is formed, which by adjusting vapour pressure deficit (VPD) and consequently leaf transpiration can precisely control LWC. This technique is demonstrated here in a combination with microscopic fluorescence imaging of apoplastic pH (pH apo ) as indicated by the excitation ratio of the pH sensitive dye OregonGreen. Initial results indicate that pH apo of the adaxial epidermis of Vicia faba is linearly related to reductions in LWC. Conclusions Using this setup, constant LWC levels, step changes or ramps can be experimentally applied while simultaneously measuring physiological responses. The example experiments demonstrate that bringing LWC under experimental control in this way allows better controlled and more repeatable experiments to probe quantitative relationships between LWC and signaling and regulatory processes.

Assessment of drought resistance in sorghum CMS lines based on various sterility sources

Background. Global climate changes have recently led to a more frequent occurrence of adverse factors and a decrease in the productivity of major crops. Sorghum is a highly drought-resistant crop that can tolerate long-term soil and air droughts with much lower harvest losses than wheat or barley. It is important to understand physiological mechanisms affecting drought tolerance when breeding efforts are aimed at improving the adaptability to abiotic conditions and productivity of sorghum hybrids.Materials and methods. Twenty sterile lines of grain sorghum with 8 types of CMS were studied in 2019 and 2020 in the arid conditions of Saratov Province. Indicators of the leaf water regime were assessed according to VIR’s guidelines. Statistical processing of the research results was performed using the AGROS 2.09 software.Results. The indicators of the leaf water regime that reflected differentiated responses of the CMS-line plants to the prevailing water and temperature stressors during the critical flowering period for sorghum were analyzed. Four CMS lines were identified according to the chosen set of indicators: they manifested 71.13–72.02% of total water content, 5.26–9.08% of water deficit, and 57.40–83.17% of water retention capacity on average for the two years of research. For the first time, the effect of CMS in sorghum on the manifestation of water regime indicators was registered. In isonuclear CMS lines, the greatest effect on drought resistance was shown by cytoplasm A3 versus A4 (with the Zheltozernoe 10 genome), cytoplasm A5 versus A1 (with the Karlik 4v genome), and M35-1A versus the analog on cytoplasm 9E (with the Pischevoe 614 genome).Conclusion. It is shown that genetically different types of sterility can be used in breeding practice to increase the resistance to abiotic stressors in components of F1 crosses and hybrids.

Performance and blood lipide profile of cockerel aged 0-7 weeks that were given sambiloto leaf water extract (Andrographis paniculata ness) through drinking water

This study aims to examine the effect of adding water extract of Sambiloto (Andrographis paniculata Ness) to drinking water on the performance and blood lipids profilem of cockerel aged 0-7 weeks. This study was conducted in the village of Cepaka, Kediri, Tabanan, Bali. Using A total of 200 birds of aged 1 day old chick laying hens males.. The experimental design used was a Completely Randomized Design (CRD) with four treatments and five replications so that there were 20 units, each replicate using 10 chickens. The treatments were: (A) Drinking water without the addition of extract sambiloto leaf water, (B) drinking water with the addition of sambiloto leaf water extract 2 ml/l , (C) drinking water with the addition of sambiloto leaf water extract 4 ml/l and (D) drinking water with the addition of sambiloto leaf water extract 6 ml/L The variables observed in this study were performance, carcass, blood lipid profile, digestive tract microbes and economic aspec. The results showed that the administration of sambiloto leaf water extract not significantly different (P>0.05) on ration consumption, drinking water consumption, final body weight, FCR, blood lipid profile, total coliform and E.coly and significantly different (P<0.05) on carcass percentage, carcass composition.

Changes in Transpiration and Leaf Water Potential in Douglas-Fir Trees following Douglas-Fir Beetle Attack and Mechanical Girdling

Bark beetles and their associated fungi kill trees readily, but we often ignore which organism is the leading cause of tree mortality. While phloem feeding beetles inhibit photosynthate transport, their associated fungi block the tracheids disrupting transpiration. Within the family Pinaceae, knowledge of tree physiological decline following bark beetle and associated fungi colonization is limited to the genus Pinus. Here we investigate the physiological response of Pseudotsuga (P. menziesii) to bark beetles or its fungi. We hypothesized that fungi block water transport in Douglas-fir causing faster mortality than by bark beetle activity alone. We successfully lured Douglas-fir beetle to attack a subset of trees in our experimental area using pheromones and compared Beetle-Killed trees with mechanically Girdled, and Control trees. During spring snowmelt, nine months after treatments were applied, Control, Girdled, and five trees that Survived beetle attack had higher transpiration rates and less negative pre-dawn water potential than five Beetle-Killed trees. Declines in transpiration and leaf water potential in our Beetle-Killed trees occurred much earlier than those in studies of beetle-attacked lodgepole pines, suggesting stronger defensive traits in Douglas-fir. Our data suggest that, as in pines, bark beetle-associated fungi are the leading cause of mortality in Douglas-fir beetle-attacked trees.

Variation and adaptation of leaf water content among species, communities, and biomes

Leaf water content (LWC) is essential for the physiological activities in plants, but its spatial variation and the underlying mechanisms in natural plant communities are unclear. In this study, we measured the LWC of 5641 plant species from 72 natural communities in China, covering most terrestrial ecosystems, to answer these questions. Our results showed that LWC, on average, was 0.690 g g–1, and was significantly higher in forests and deserts than in grasslands. LWC was significantly different among different plant life forms, and ranked on averages in the following order: herbs > shrubs > trees. Interestingly, LWC decreased with increasing humidity and increased in dry environments. Furthermore, the variations of LWC in plant communities were higher in arid areas and those species with lower LWC in a plant community were more sensitive to changing environments. These results demonstrated the adaptations of plants to water regime in their habitats. Although, phylogeny has no significant effect on LWC, plant species both in forests and grasslands evolve toward higher LWC. Variations of LWC from species to community to biome represent the cost-effective strategy of plants, where plant species in drier environment require higher input to keep higher LWC to balance water availability and heat regulation. This systematic investigation fills the gaps on how LWC varies spatially and clarifies the different adaptation mechanisms regulating LWC across scales.

Study of Genetic Analysis of Physiological Attributes under Normal and Drought Conditions in Gossypium hirsutum L.

The aim of this study was to identify the suprior cotton genotypes with improved physiological characteristics under drought conditions. On the bais of root-shoot charcteristics, five genoypes of G. hirsutum were identified as drought tolerant and three genotypes screened out as drought susceptible. The field screening experiment were carried out to validate the findigs of root-shoot screening sudy on the basis of physiological as well as agronomical chracteristics. Both drought tolerant and susceptible genotypes were grown in glass house in pots and followed line x tester mating desighn to cross these genotyps. Parents with their fiftenn offsprings were grown in field conditions in very next cotton season for further analysis. Analysis of variance showed the existence of significant variations among the accessions for all the physiological parameters i.e, osmotic potential, relative water content, cell injury, leaf water potential, excised leaf water loss, stomatal conductance, photosynthesis rate and transpiration rate. Further, among parents line, MS-64 and tester, BH-176 showed superior performance under water scarce conditions. Among the crosses COOKER-315 x Cyto-62 and GS-444 x MPS-11 were better perfomed for high yielding parametrs. The results showed that these two combinations might be helpful to develop drought resistant germplasm on large scale.