Reduction in cadmium accumulation in japonica rice grains by CRISPR/Cas9-mediated editing of OsNRAMP5

Cadmium (Cd) intake is harmful to human health and Cd contamination in rice grains represents a severe threat to those consuming rice as a staple food. Knockout of Cd transporters is a promising strategy to reduce Cd accumulation in rice grains. OsNRAMP5 is the major transporter for Cd and manganese (Mn) uptake in rice. Nevertheless, it is uncertain whether knockout of OsNRAMP5 is applicable to produce low Cd rice without affecting plant growth and grain yield. In this study, we adopted CRISPR/Cas9-based gene editing technology to knock out OsNRAMP5 in two japonica varieties. We generated three independent transgene-free osnramp5 mutants and investigated the effect of osnramp5 mutations on Cd accumulation and plant growth. Hydroponic experiments showed that plant growth and chlorophyll content were significantly reduced in osnramp5 mutants at low Mn conditions, and this defective growth in the mutants could be fully rescued by supply of high levels of Mn. Cd and Mn accumulation in both roots and shoots was markedly reduced in the mutants compared to that in wild-type plants. In paddy field experiments, although Cd in flag leaves and grains was greatly reduced in osnramp5 mutants, some agronomic traits including plant height, seed setting rate, and grain number per panicle were affected in the mutants, which ultimately caused a mild reduction in grain yield. The reduced plant growth in the mutants can be attributed to a marked decrease in Mn accumulation. Our results reveal that the manipulation of OsNRAMP5 should be treated with caution: When assessing the applicability of osnramp5 mutants, soil pH and soil water content in paddy fields need to be taken into consideration, since they might affect the levels of available Mn in the soil and consequently determine the effect of the mutation on grain yield.     

Herbicide options for effective weed management in dry direct-seeded rice under scented rice-wheat rotation of western Indo-Gangetic Plains

Farmers' participatory field trials were conducted at Madhuban, and Taraori, the two participatory experimental sites/locations of the Cereal Systems Initiative for South Asia (CSISA), a collaborative project of IRRI and CIMMYT in Karnal district of Haryana, India, during Kharif (wet season) 2010 and 2011. This research aimed to evaluate preemergence (PRE) and postemergence (POST) herbicides for providing feasible and economically viable weed management options to farmers for predominant scented rice varieties. Treatments with pendimethalin PRE fb bispyribac-sodium + azimsulfuron POST had lower weed biomass at 45 days after sowing (DAS). At Madhuban, highest grain yield of scented basmati rice (3.43 t ha⁻¹) was recorded with the sequential application of pendimethalin PRE fb bispyribac-sodium + azimsulfuron POST. However, at Taraori, yields were similar with pendimethalin or oxadiargyl PRE fb bispyribac-sodium and/or azimsulfuron POST. Applying oxadiargyl by mixing with sand onto flooded field was less effective than spray applications in non-flooded field. The benefit-cost ratio of rice crop was higher with herbicide treatments at both sites as compared with the non-treated weed-free check except single PRE and POST applications and sequential application of oxadiargyl PRE fb oxadiargyl PRE. In a separate experiment conducted at Nagla and Taraori sites, scented rice cultivars' ('CSR 30′ and 'Pusa 1121′) tolerance to three rates of azimsulfuron (15, 25, and 35 g ai ha⁻¹) was evaluated over two years (2010 and 2011). CSR 30 (superfine, scented) was more sensitive to higher rates (35 g ai ha⁻¹) of azimsulfuron as compared to Pusa 1121 (fine, scented). Crop injuries were 8 and 28% in case of CSR 30; 5 and 15% in Pusa 1121 when applied with azimsulfuron 25 and 35 g ai ha⁻¹, respectively. Azimsulfuron applied at 35 g ai ha⁻¹ reduced yield in both cultivars but in CSR 30 yield reduction was twofold (11.5%) as that of Pusa 1121 (5.2%).     

Fusarium solani Upregulated Sesquiterpene Synthase Expression,Sesquiterpene Production and Allelopathic Activity in Piper betle L.

Activators of sesquiterpene synthase (STS) gene expression and sesquiterpene production in Piper betle L. were examined using quantitative real time PCR and gas chromatography mass spectrometry methods, and the allelopathic activity of untreated and Fusarium solani-treated betel extracts was tested on seed germination and on the shoot and root growth of Thai rice variety PSL2 (Oryza sativa cv. Phitsanulok 2) and three dominant paddy weeds (Eclipta prostrata, Echinochloa crus-galli and Chloris barbata). The results demonstrated that F. solani dramatically upregulated STS expression and productions of β-cubebene, β-caryophyllene and germacrene D sesquiterpene when compared with the untreated control, and that betel extracts had a greater inhibitory effect on weeds than on rice. The effects were more clearly detected on seed germination and root growth than on shoot growth, and they were found to be dose-dependent. It is also noted that F. solani-treated extract had stronger effects than the untreated extract. The species most sensitive to the allelopathic effects was C. barbata, germination of which was completely inhibited even at a dose of 0.1 mg/mL untreated extract. With regards to rice, although betel extract at 1.0 mg/mL showed no inhibition on germination, it affected the elongation of rice roots, in addition to those of the tested weeds. The obtained data suggested that F. solani has potential as an activator of sesquiterpene allelochemical production via STS expression, the latter leading to the treated betel extract having a stronger phytotoxic effect. These results were beneficial in the promotion of natural herbicide production using biotechnology.     

成渝地区葡萄园营养状况初步研究与分析

在成渝地区具有代表性的葡萄园内进行了叶样和土样采集分析,结果表明:与标准值对比,大部分葡萄园内叶片中营养元素P与Mg含量水平较低,微量元素Mn与Fe含量水平则偏高；在大量使用有机肥的葡萄园内,土壤中速效性的营养元素N、P、K含量水平相对较高.     

An improved method for extraction of sorghum polymeric protein complexes

A method for fractionating sorghum proteins using extraction solvents and techniques designed to obtain polymeric protein structures (especially disulfide linked) was developed. Extraction and separation conditions were optimized in terms of completeness of protein extraction, sample stability, and analytical resolution. After pre-extraction of albumins and globulins, a 3-step sequential procedure involving no reducing agents was applied to ground whole sorghum flour. The three fractions obtained represented proportionally different protein polymer contents and molecular weight distribution as evidenced by comparative size exclusion chromatography. Protein composition also varied among the extracts with differences in kafirin composition and non-kafirin proteins detected in the fractions by RP-HPLC and SDS-PAGE analysis. The ability to quantify and further characterize sorghum polymeric protein complexes will be useful for additional studies linking protein structures with functionality and digestibility and variations for these properties within diverse sorghum germplasm.     

密集烤房不同循环风机烘烤烟叶的色素降解及感官质量

采用三速和单速循环风机,研究密集烤房不同循环风机对烤烟色素及感官质量的影响.结果表明:采用三速循环风机烤后烟叶的叶绿素a、叶绿素b含量分别为5.10、167.74 μg/g,分别为单速循环风机的72.11％和93.30％;叶黄素、β-胡萝卜素、类胡萝卜素含量分别为0.84、155.56、156.40 μg/g,分别为单...     

温室一茄多果快速育成技术

随着嫁接技术在蔬菜育苗中的广泛应用,根据近年来兴起的一茄多果嫁接技术与园艺景观造型相结合的趋势,介绍了一种改进的一茄多果嫁接技术,技术的流程更简洁,也更易于操作,可使经济效益与人文景观效果得到共同提升。     

基于SWOT-AHP分析的内蒙古农牧业可持续发展研究

摘要：通过运用SWOT分析法，从多个维度确定影响内蒙古农牧业发展的因素，再运用AHP分析法，将SWOT分析的影响因素作为指标层，邀请专家打分构造判断矩阵，将其量化的指标按其重要性进行排序。通过计算总优势、劣势、机遇、威胁力度，绘制战略四边形，并且计算战略四边形重心，判断战略定位，最后进行战略选择。结果显示内蒙古农牧业可持续发展中机遇>优势>劣势>威胁。战略中心位于第一象限内，说明应该采取开拓性战略，战略方位角=49.14°，说明目前处于机遇期。因此内蒙古农牧业应该制定积极的发展战略，依靠内部优势，充分利用外部机会。     

合欢枯萎病菌的生物学特性研究

通过组织分离法获得合欢枯萎病纯茵种，并以常规方法对合欢枯萎病病茵的生物学特性进行了研究，其结果表明，该茵可在PDA、PSA以及合欢的根、茎、叶培养基上生长，在PDA及PSA上的生长情况基本一致，且茵丝旺盛，而在合欢根、茎、叶培养基中的生长情况稍差；该茵的生长温度为5～32℃，最适生长温度为23—29℃；孢子在葡萄糖培养...     

Mapping soil salinity and pH across an estuarine and alluvial plain using electromagnetic and digital elevation model data

Increasing pressures from agriculture and urbanization have resulted in drainage of many floodplains along the eastern Australian coastline, which are underlain by sulphidic sediments, to lower water tables and reduce soil salinity. This leads to oxidation of the sediments with a rapid decline in pH and an increase in salinity. Accurately mapping soil salinity and pH in coastal acid sulphate soil (CASS) landscapes is therefore important. One required map is the extent of highly acidic (i.e. pH < 4.5) areas, so that the application of alkaline amendments (e.g. lime) to neutralize the acid produced can be specifically targeted to the variation in pH. One approach is to use digital soil mapping (DSM) using ancillary information, such as an EM38, digital elevation models (DEM – elevation) and trend surface parameters (east and north). We used an EM38 in the horizontal (EM38h) and vertical (EM38v) modes together with elevation data to develop multiple linear regressions (MLR) for predicting EC_1:5 and pH. For pH, best results were achieved when the EM38 EC_a data were log‐transformed. By comparing MLR models using REML analysis, we found that using all ancillary data was optimal for mapping EC_1:5, whereas the best predictors for pH were north, log‐EM38v and elevation. Using residual maximum likelihood (REML), the final EC_1:5 and pH maps produced were consistent with previously defined soil landscape units, particularly CASS. The DSM approach used is amenable for mapping saline soils and identifying areas requiring the application of lime to manage acidic soil conditions in CASS landscape.