Enhancing the nutritional value of food crops is a means of improving human nutrition and health. We report here the positional cloning of Gpc-B1, a wheat quantitative trait locus associated with ...increased grain protein, zinc, and iron content. The ancestral wild wheat allele encodes a NAC transcription factor (NAM-B1) that accelerates senescence and increases nutrient remobilization from leaves to developing grains, whereas modern wheat varieties carry a nonfunctional NAM-B1 allele. Reduction in RNA levels of the multiple NAM homologs by RNA interference delayed senescence by more than 3 weeks and reduced wheat grain protein, zinc, and iron content by more than 30%.
Zadnjih godina poljoprivrednici se sve više susreću s polaganim rastom temperatura zraka, a koje tijekom ljetnih mjeseci najčešće prati i nedostatak oborina. U Hrvatskoj nedovoljnu opskrbu vodom ...najlakše opažamo za kasne jarine poput kukuruza i soje jer se njihova aktivna vegetacija najvećim dijelom odvija tijekom najtoplijeg i najsušnijeg dijela godine (srpnja i kolovoza). Općenito se može reći da sa sve dužim razdobljem nedostatka vode tijekom vegetacije dolazi do sve većih šteta u usjevu jer biljke zaostaju u rastu, imaju manju veličinu lisne površine, a time će na kraju i njihov prirod odnosno prinos biti značajno umanjen. Suša koja nastupi za vrijeme kritičnog perioda za vodu najviše smanjuje prirod odnosno prinos uzgajane kulture, a u ekstremnim slučajevima mogu nastati i potpune štete. No, suša ima prvenstveno jako negativan utjecaj na prinos, dok je njen učinak na kakvoću prinosa odnosno priroda relativno malen. U stručnom radu se iznosi negativan učinak visokih temperatura zraka i nedostatka vode na prinos i kakvoću kukuruza i soje, dvije naše najraširenije jare kulture.
Crop producers are becoming aware of a slow rise in air temperatures in the past years, which is often coupled with a lack of precipitation during the summer months. In Croatia, insufficient water supply (water stress) is easily observed for late spring crops such as maize and soybean since their growing season is occurring during the hottest and driest part of the year (July and August). In general, crop damage is increased with the extended period of water shortage during the growing season because of slower growth and lower leaf area, which in turn, result in greatly reduced biological and economic yield. A severe drought occurring during the critical period for water has the largest negative impact on the biological and economic yield of field crops, and in some cases, may result in total yield loss. Consequently, the drought primarily affects the biological and economic yield of arable crops, while its effect on the quality is less evident. This professional paper presents the negative effect of high air temperatures and water shortage on the yield and quality of maize and soybeans, two most widely grown spring crops in Croatia.
Cytokinin Oxidase Regulates Rice Grain Production Ashikari, Motoyuki; Sakakibara, Hitoshi; Lin, Shaoyang ...
Science (American Association for the Advancement of Science),
07/2005, Letnik:
309, Številka:
5735
Journal Article
Recenzirano
Odprti dostop
Most agriculturally important traits are regulated by genes known as quantitative trait loci (QTLs) derived from natural allelic variations. We here show that a QTL that increases grain productivity ...in rice, Gn1a, is a gene for cytokinin oxidase/dehydrogenase (OsCKX2), an enzyme that degrades the phytohormone cytokinin. Reduced expression of OsCKX2 causes cytokinin accumulation in inflorescence meristems and increases the number of reproductive organs, resulting in enhanced grain yield. QTL pyramiding to combine loci for grain number and plant height in the same genetic background generated lines exhibiting both beneficial traits. These results provide a strategy for tailormade crop improvement.
Sulfur deficiency in plants has severe impacts on both growth and nutrient composition. Fumigation with sub-lethal concentrations of H2S facilitates the supply of reduced sulfur via the leaves while ...sulfate is depleted from the roots. This restores growth while sulfate levels in the plant tissue remain low. In the present study this system was used to reveal interactions of sulfur with other nutrients in the plant and to ascertain whether these changes are due to the absence or presence of sulfate or rather to changes in growth and organic sulfur. There was a complex reaction of the mineral composition to sulfur deficiency, however, the changes in content of many nutrients were prevented by H2S fumigation. Under sulfur deficiency these nutrients accumulated on a fresh weight basis but were diluted on a dry weight basis, presumably due to a higher dry matter content. The pattern differed, however, between leaves and roots which led to changes in shoot to root partitioning. Only the potassium, molybdenum and zinc contents were strongly linked to the sulfate supply. Potassium was the only nutrient amongst those measured which showed a positive correlation with sulfur content in shoots, highlighting a role as a counter cation for sulfate during xylem loading and vacuolar storage in leaves. This was supported by an accumulation of potassium in roots of the sulfur-deprived plants. Molybdenum and zinc increased substantially under sulfur deficiency, which was only partly prevented by H2S fumigation. While the causes of increased molybdenum under sulfur deficiency have been previously studied, the relation between sulfate and zinc uptake needs further clarification.
Strawberry is an important fruit crop within the UK. To reduce the impact of soil-borne diseases and extend the production season, more than half of the UK strawberry production is now in substrate ...(predominantly coir) under protection. Substrates such as coir are usually depleted of microbes including arbuscular mycorrhizal fungi (AMF) and consequently the introduction of beneficial microbes is likely to benefit commercial cropping systems. Inoculating strawberry plants in substrate other than coir has been shown to increase plants tolerance to soil-borne pathogens and water stress. We carried out studies to investigate whether AMF could improve strawberry production in coir under low nitrogen input and regulated deficit irrigation. Application of AMF led to an appreciable increase in the size and number of class I fruit, especially under either deficient irrigation or low nitrogen input condition. However, root length colonization by AMF was reduced in strawberry grown in coir compared to soil and Terragreen. Furthermore, the appearance of AMF colonizing strawberry and maize roots grown in coir showed some physical differences from the structure in colonized roots in soil and Terragreen: the colonization structure appeared to be more compact and smaller in coir.
Iron deficiency is a major human nutritional problem wherever plant-based diets are common. Using synchrotron x-ray fluorescence microtomography to directly visualize iron in Arabidopsis seeds, we ...show that iron is localized primarily to the provascular strands of the embryo. This localization is completely abolished when the vacuolar iron uptake transporter VIT1 is disrupted. Vacuolar iron storage is also critical for seedling development because vit1-1 seedlings grow poorly when iron is limiting. We have uncovered a fundamental aspect of seed biology that will ultimately aid the development of nutrient-rich seed, benefiting both human health and agricultural productivity.
Abstract Milk thistle Silybum marianum (L.) Gaertn. is one of the most researched medicinal plants, but at the same time it belongs to crops with wide industry potential whose growth requirements for ...marginal agroecological conditions or the response to agronomic interventions has not yet been sufficiently studied. The aim of the present research was to verify the effect of mineral nutrition (NPK 200 kg/ha) and humic acids applied to the soil (HUMAC Agro 250 kg/ha) on the main biometric parameters and the intensity of photosynthesis of milk thistle grown under less favourable climatic conditions of the semi-cold and humid foothills in Central Europe. The highest seed yield was achieved with the NPK variant in terms of dry matter 0.534 t/ha, in the HUMAC Agro variant 0.254 t/ha and with the untreated control 0.087 t/ha. The soil before the trial establishment was characterised by low nutrient content. The use of mineral fertiliser on NPK treatment eliminated the influence of low PK nutrients content of the soil, influencing the crop growth and yield/quality, while no doses of NPK were used on the HUMAC Agro variant and the untreated control. For both of the two sequences created (temperature and light), the highest photosynthesis rate was measured on untreated control (20.115 and 12.386 mmol/m 2 /s 1 ), markedly lower on HUMAC Agro (16.386 and 9.653 mmol/m 2 /s 1 ) – and the lowest on the NPK (10.933 and 7.813 mmol/m 2 /s 1 , respectively), in inverse proportion to the crop yield. Therefore, the size of the leaf area of the crop was decisive for the increased crop yield. The polynomial trend line of the photosynthesis rate according to the temperature sequence shows the photosynthesis rate and the torrential decrease by temperature increasing on untreated control compared with both treated variants. Both of these threats, mineral nutrition and use of humic preparations to soil, although they reduce the photosynthesis rate, have a wide range of complex effects that provide an opportunity to optimise the growth and yield of milk thistle. Ideally, the mineral nutrition and humic preparations should be used in combination with the crop of milk thistle for medicinal and energy purposes.
Field Pennycress (Thlaspi arvense L.) is a member of the mustard family and may be grown as a winter crop between traditional summer crops to produce renewable biomass for renewable diesel and jet ...fuel. This paper estimated total annual biofuel production potential of 15 million cubic metres from rotation between corn and soybeans on 16.2 million hectares in the Midwest without impact on food production. This study also investigated the life cycle greenhouse gas (GHG) emissions and energy balance of pennycress-derived Hydroprocessed Renewable Jet (HRJ) fuel and Renewable Diesel (RD). Both system expansion and allocation approaches were applied to distribute environmental impacts among products and co-products along the life cycle of each biofuel. The life cycle GHG emissions (excluding land use change) for RD and HRJ range from 13 to 41 g MJ−1 (CO2 eq.) and −18 to 45 g MJ−1 (CO2 eq.), respectively, depending on how the co-products are credited. The majority of the energy required for each biofuel product is derived from renewable biomass as opposed to non renewable fossil. The fossil energy consumptions are considerably lower than the petroleum fuels. Scenario analyses were also conducted to determine response to model assumptions, including nitrogen fertilizer application rate, nitrogen content in crop residues, and sources of H2. The results show that pennycress derived biofuels could qualify as advanced biofuels and as biomass-based diesel as defined by the Renewable Fuels Standard (RFS2).
► Estimated total pennycress derived biofuel production potential of 15 GL y−1 ► Rotation between corn and soybeans without impact on food production. ► The GHG of RD and HRJ show over 50% of reductions compared to petroleum baseline. ► The majority of the energy required is from renewable biomass. ► The fossil energy consumptions are considerably lower than the petroleum fuels.
The lignocellulosic materials are cheap and readily available either in the form of agricultural waste or forest residues. These materials can be used as a source for energy production either in the ...gaseous form (CO, H2 etc) or in liquid form (ethanol, butanol etc) to meet the rising demand of energy. The reign of lignocellulosic materials for energy production is a proven fact in this era of energy research. The present study focuses on characterization of three biomass samples namely areca nut husk (Areca catheu), moj (Albizia lucida) and bonbogori (Ziziphus rugosa), available in the region of North-East India. Physical and chemical analysis of these lignocellulosic biomass samples were performed using X-ray diffraction techniques, thermogravimetric analysis, FTIR, Raman spectroscopy and CHNSO analysis. Maximum crystalinity was observed in areca nut husk fiber (63.84%) followed by moj (46.43%) and bonbogori (42.46%). The calorific values of all the biomasses were found within the range of 17 MJ/kg to 22 MJ/kg. All these properties combined together per se shows that areca nut husk, bonbogori and moj are potential sources for biofuel production.
► Non-conventional biomasses were considered in this study. ► Complete characterization of these biomasses are reported. ► Maximum crystalinity was observed in areca nut husk fiber followed by moj and bonbogori. ► Results confirmed that these biomasses can be utilized for biofuel production.
Spectral properties of a wheat canopy with vegetation fraction (VF) from 0% to 100% in visible and near-infrared (NIR) ranges of the spectrum were studied in order to devise a technique for remote ...estimation of VF. When VF was <60%, from emergence till middle of the elongation stage, four distinct, and quite independent, spectral bands of reflectance existed in the visible range of the spectrum: 400 to 500 nm, 530 to 600 nm, near 670 nm, and around 700 nm. When VF was between 60% and 100%, reflectance in the NIR leveled off or even decreases with an increase of VF. The decreased reflectance in the NIR, occurring at or near the midseason, can be a limiting factor in the use of that spectral region for VF estimation. It was found that for VF>60%, the information content of reflectance spectra in visible range can be expressed by only two independent pairs of spectral bands: (1) the blue from 400 to 500 nm and the red near 670 nm; (2) the green around 550 nm and the red edge region near 700 nm. We propose using only the visible range of the spectrum to quantitatively estimate VF. The green (as well as a 700-nm band) and the red (near 670 nm) reflectances were used in developing new indices, which were linearly proportional to wheat VF ranging from 0% to 100%. The Atmospherically Resistant Vegetation Index (ARVI) concept was used to correct indices for atmospheric effects. Visible Atmospherically Resistant Index in the form VARI=(
R
green−
R
red)/(
R
green+
R
red−
R
blue) was found to be minimally sensitive to atmospheric effects allowing estimation of VF with an error of <10% in a wide range of atmospheric optical thickness. Validation of the newly suggested technique was carried out using wheat independent data sets and reflectance data obtained for cornfields in Nebraska. Predicted green VF was compared with retrieved from digital images. Despite the fact that the reflectance contrast among the visible channels is much smaller than between the visible and NIR, the sensitivity of suggested indices to moderate to high values of VF is much higher than for the Normalized Difference Vegetation Index (NDVI), and the error in VF prediction did not exceed 10%. Suggested indices will complement the widely used NDVI, ARVI, Soil Adjusted Vegetation Index (SAVI) and others, which are based on the red and the NIR bands in VF estimation, and also Green Atmospherically Resistant Index (GARI), which is based on the green and the NIR bands.
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