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101.
Abstract This paper presents an interdisciplinary approach to crop improvement that links physiology with plant breeding and simulation modelling to enhance the selection of high‐yielding, drought‐tolerant varieties. In a series of field experiments in Queensland, Australia, we found that the yield of CIMMYT wheat line SeriM82 ranged from 6% to 28% greater than the current cultivar Hartog. Physiological studies on the adaptive traits revealed that SeriM82 had a narrower root architecture and extracted more soil moisture, particularly deep in the profile. Results of a simulation analysis of these adaptive root traits with the cropping system model APSIM for a range of rain‐fed environments in southern Queensland indicated a mean relative yield benefit of 14.5% in water‐deficit seasons. Furthermore, each additional millimetre of water extracted during grain filling generated an extra 55 kg ha?1 of grain yield. Further root studies of a large number of wheat genotypes revealed that wheat root architecture is closely linked to the angle of seminal roots at the seedling stage – a trait which is suitable for large‐scale and cost‐effective screening programmes. Overall, our results suggest that an interdisciplinary approach to crop improvement is likely to enhance the rate of yield improvement in rain‐fed crops. 相似文献
102.
《Journal of enzyme inhibition and medicinal chemistry》2013,28(1):84-91
A facile and ecofriendly synthesis of new chromonyl chalcones 3a-b from 3-formylchromone 1 and active methyl compounds 2a-b is reported under thermal solvent-free heating condition in good yields. The chromonyl chalcones 3a-b were used as intermediates under green condition for the synthesis of new bioactive pyrazoline derivatives 4a-f. The compounds were tested for antimicrobial activity by disk diffusion assay with slight modifications against Gram-positive, Gram-negative strains of bacteria as well as fungal strains. The investigation of antimicrobial screening revealed that compounds 3a-b and 4a-f showed antibacterial and antifungal activities. 相似文献
103.
Kohjiro Nagao Minami Maeda Noralyn B. Mañucat Kazumitsu Ueda 《Biochimica et Biophysica Acta (BBA)/Molecular and Cell Biology of Lipids》2013,1831(2):398-406
ATP-binding cassette protein A1 (ABCA1) plays a key role in generating high-density lipoprotein (HDL). However, the detailed mechanism of HDL formation remains unclear; in order to reveal it, chemicals that specifically block each step of HDL formation would be useful. Cyclosporine A inhibits ABCA1-mediated cholesterol efflux, but it is not clear whether this is mediated via inhibition of calcineurin. We analyzed the effects of cyclosporine A and related compounds on ABCA1 function in BHK/ABCA1 cells. Cyclosporine A, FK506, and pimecrolimus inhibited ABCA1-mediated cholesterol efflux in a concentration-dependent manner, with IC50 of 7.6, 13.6, and 7.0 μM, respectively. An mTOR inhibitor, rapamycin also inhibited ABCA1, with IC50 of 18.8 μM. The primary targets for these drugs were inhibited at much lower concentrations in BHK/ABCA1 cells, suggesting that they were not involved. Binding of [3H] cyclosporine A to purified ABCA1 could be clearly detected. Furthermore, a non-immunosuppressive cyclosporine, PSC833, inhibited ABCA1-mediated cholesterol efflux with IC50 of 1.9 μM, and efficiently competed with [3H] cyclosporine A binding to ABCA1. These results indicate that cyclosporine A and PSC833 inhibit ABCA1 via direct binding, and that the ABCA1 inhibitor PSC833 is an excellent candidate for further investigations of the detailed mechanisms underlying formation of HDL. 相似文献
104.
Modern maize hybrids in Northeast China exhibit increased yield potential and resource use efficiency despite adverse climate change 总被引:10,自引:0,他引:10
Xiaochao Chen Fanjun Chen Yanling Chen Qiang Gao Xiaoli Yang Lixing Yuan Fusuo Zhang Guohua Mi 《Global Change Biology》2013,19(3):923-936
The impact of global changes on food security is of serious concern. Breeding novel crop cultivars adaptable to climate change is one potential solution, but this approach requires an understanding of complex adaptive traits for climate‐change conditions. In this study, plant growth, nitrogen (N) uptake, and yield in relation to climatic resource use efficiency of nine representative maize cultivars released between 1973 and 2000 in China were investigated in a 2‐year field experiment under three N applications. The Hybrid‐Maize model was used to simulate maize yield potential in the period from 1973 to 2011. During the past four decades, the total thermal time (growing degree days) increased whereas the total precipitation and sunshine hours decreased. This climate change led to a reduction of maize potential yield by an average of 12.9% across different hybrids. However, the potential yield of individual hybrids increased by 118.5 kg ha?1 yr?1 with increasing year of release. From 1973 to 2000, the use efficiency of sunshine hours, thermal time, and precipitation resources increased by 37%, 40%, and 41%, respectively. The late developed hybrids showed less reduction in yield potential in current climate conditions than old cultivars, indicating some adaptation to new conditions. Since the mid‐1990s, however, the yield impact of climate change exhibited little change, and even a slight worsening for new cultivars. Modern breeding increased ear fertility and grain‐filling rate, and delayed leaf senescence without modification in net photosynthetic rate. The trade‐off associated with delayed leaf senescence was decreased grain N concentration rather than increased plant N uptake, therefore N agronomic efficiency increased simultaneously. It is concluded that modern maize hybrids tolerate the climatic changes mainly by constitutively optimizing plant productivity. Maize breeding programs in the future should pay more attention to cope with the limiting climate factors specifically. 相似文献
105.
106.
107.
Jihae Park 《Journal of phycology》2020,56(2):549-557
The physiological and biochemical changes in the green macroalga Ulva pertusa during the progression of sporulation have been characterized. The transition from the vegetative to the sporulation stage was accompanied by an increase in chlorophyll a (Chl a), chlorophyll b (Chl b), and carotenoid content, as well as an increase in DPPH scavenging and responsiveness to diphenylamine. However, oxygen evolution and maximum electron transport rate decreased. The discrepancy between photosynthetic performance and pigment content might relate to the self-shading of spores within a sporangium. Spore-forming U. pertusa thalli were low-light-adapted, due to an increase in the number of photosynthetic units. Decreased electron transport during sporulation might trigger sporulation, as for some cyanobacteria and other Ulva spp., via oxidization of the plastoquinone pool and cyclic phosphorylation, thus producing ATP to generate carbon and nitrogen skeletons required for spores. It is thus concluded that carotenoids function both in spore initiation and/or maturation and in their photoprotection. 相似文献
108.
Jiqiang Zhang Ziru Niu Tianhua Li Yanqiang Wu Rui Xi Yuhua Li Guanghua Li Jialin Hou 《Phyton》2020,89(1):147-166
Considering the current low level of mechanization for domestic green
onion planting and the high labor intensity of artificial planting, a 2ZYX-2 green
onion ditching and transplanting machine, which can complete ditching, ridging,
transplanting, repression, soil covering and other operations, is designed in this
study. The Central Composite test design method was carried out with the speed
of the transplanting machine, the depth of the opener and the horizontal position
of the opener as the experimental factors and with the qualification ratio of
perpendicularity, the variation coefficient of the plant spacing and the
qualification ratio of the planting depth as the test index. Through the analysis of
the model interaction and response surface, the change laws that the influence
the machine’s forward speed, the depth of the opener and the horizontal position
of the opener were studied. The regression model was optimized by
Design-Expert 8.0.6 software, and the accuracy of the predicted results was
verified by experiments. The optimal working parameters showed that the
forward speed of the machine was 0.06 m/s, the depth of the opener was 102 mm,
and the horizontal position of the opener was 29 mm. Under conditions of
optimal working parameters, the qualification rate of the verticality was 86.83%,
the coefficient of variation for the plant spacing was 2.77, and the pass rate of
planting depth was 88.26%. The research related to the thesis can provide a
reference for the mechanized planting of green onion, which is of great
significance to the cost-effectiveness of the green onion industry. 相似文献
109.
Katie Parker Krista Ryall Brian H. Aukema Peter Silk 《Entomologia Experimentalis et Applicata》2020,168(2):166-173
The emerald ash borer (EAB), Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), is a highly destructive primary pest of ash (Fraxinus sp., Oleaceae) trees outside of its native range. Ash is an important component of many ecosystems and its loss would be detrimental to both the economy and the environment. The present study aimed to improve our understanding of the effectiveness of green sticky prism traps baited with host kairomone and insect pheromone lures for A. planipennis and to collect data for modelling the range of attraction of the pheromone (3Z)-dodecen-12-olide [(3Z)-lactone]. Traps were deployed over a single flight season in urban locations of Ontario, Canada, with low densities of EAB. Traps were placed in pairs of trees separated by not more than 25 m. All traps contained the host kairomone, (3Z)-hexenol, with the remaining half in each pairing additionally baited with (3Z)-lactone pheromone. Both lure types were highly effective in capturing EAB, with >90% detection rates overall. However, traps baited with the lactone pheromone and host volatile lures doubled trap captures of EAB over distances of at least 25 m from the nearest traps baited with only host volatiles. Although the baseline detection rate of traps containing (3Z)-hexenol alone is not significantly reduced compared with traps containing (3Z)-lactone, the overall trap effectiveness is significantly increased when (3Z)-lactone is present. The implications for the use of (3Z)-lactone at 3 mg per septum dose in an early warning trapping system are discussed. Trap layout methods and risk-based analysis models can now be further refined by including these data about the attractive range of lures and their behaviour in different plot environments. 相似文献
110.
Daniela Calzia Laura Ottaggio Alessandro Cora Giorgia Chiappori Paola Cuccarolo Enrico Cappelli Alberto Izzotti Sara Tavella Paolo Degan 《Journal of cellular physiology》2020,235(4):3508-3518
Muscle loss is a major problem for many in lifetime. Muscle and bone degeneration has also been observed in individuals exposed to microgravity and in unloading conditions. C2C12 myoblst cells are able to form myotubes, and myofibers and these cells have been employed for muscle regeneration purposes and in myogenic regeneration and transplantation studies. We exposed C2C12 cells in an random position machine to simulate microgravity and study the energy and the biochemical challenges associated with this treatment. Simulated microgravity exposed C2C12 cells maintain positive proliferation indices and delay the differentiation process for several days. On the other hand this treatment significantly alters many of the biochemical and the metabolic characteristics of the cell cultures including calcium homeostasis. Recent data have shown that these perturbations are due to the inhibition of the ryanodine receptors on the membranes of intracellular calcium stores. We were able to reverse this perturbations treating cells with thapsigargin which prevents the segregation of intracellular calcium ions in the mitochondria and in the sarco/endoplasmic reticula. Calcium homeostasis appear a key target of microgravity exposure. In conclusion, in this study we reported some of the effects induced by the exposure of C2C12 cell cultures to simulated microgravity. The promising information obtained is of fundamental importance in the hope to employ this protocol in the field of regenerative medicine 相似文献