大豆抗逆基因GmDREB3启动子的克隆及调控区段分析

GmDREB3基因能提高转基因烟草和拟南芥的抗逆性。利用SiteFinding-PCR技术, 从大豆品种铁丰8号基因组中分离到大豆抗逆基因GmDREB3启动子片段, 长度1 648 bp。该片段富含A/T碱基, 还含有TATA-box、低温响应元件MYC及其他顺式元件MYB、CAAT-box等。将该启动子分区段与GUS报告基因连接构建表达载体, 利用基因枪法转化小麦愈伤组织, 并进行干旱、高盐、低温等处理, 通过组织化学染色和GUS荧光定量测定分析各区段调控元件的活性。结果表明, 在干旱和低温的诱导下, 该启动子能激活下游GUS基因的表达, 在–285 ~ –1 117区域存在与低温和干旱应答有关的重要调控元件, 在–1 464 ~ –1 648区域内存在抑制启动子活性的调控元件。由此推断, 在逆境条件下通过启动子区域正、负调控元件的共同作用, 使GmDREB3基因的表达维持在一个恰当的水平。     

Volatile metabolome and transcriptome reveal fragrance release rhythm and molecular mechanisms of Rosa yangii

Rose is a highly significant ornamental plant with substantial edible and medicinal value, cultivated worldwide primarily for perfume production. Recently, Rosa yangii, a new species found in northwestern Yunnan, China, has drawn attention due to its strong sweet scented flowers. In this study, the floral components of R. yangii were extracted at different flowering stages using solid phase micro extraction (SPME) and analyzed through gas chromatography–mass spectrometry (GC–MS). A total of 131 volatile organic compounds (VOCs) were detected from R. yangii, including 69 odor compounds. The production and release of floral VOCs were the highest during the initial-open stage, making it the most suitable time for harvesting as a significant number of floral components were synthesized and preserved. The analysis of the odor activity values (OAV) highlighted several key aromatic ingredients of R. yangii, such as eugenol, methyleugenol, benzeneacetaldehyde and phenylethylalcohol, heptanal, decanal, (E)-2-hexen-1-yl acetate, caryophyllene, and others. Metabolome and time-order gene co-expression networks (TO-GCN) revealed that VOCs and benzenoids/phenylpropanoids, along with associated genes, played a pivotal role in the overall floral regulatory network of R. yangii. MYB and bHLH were identified as the essential regulatory factors governing the regulation of eugenol synthase (EGS) and isoeugenol synthase (IGS), consequently influencing the sweet scent of R. yangii. The findings of this study provide a scientific foundation for enhancing fragrance through molecular breeding of ornamental plants. Furthermore, the study facilitated the development and utilization of this new plant’s essential oil material in various industries, including food storage, aromatherapy, cosmetic, and perfumery.     

Spatial prediction of saline and sodic soils in rice‒shrimp farming land by using integrated artificial neural network/regression model and kriging

In the context of widespread saline and sodic soil, mapping and monitoring spatial distribution of soil salinity and sodicity are important for utilization and management in agriculture lands. In this study, two-stage assessment was proposed to predict spatial distribution of saline and sodic soils. First, artificial neural network (ANN) and multiple linear regressions (MLR) model were used to predict sodium adsorption ratio (SAR) and exchangeable sodium percentage (ESP) based on soil electrical conductivity (EC) and pH. Then, the Kriging interpolation method combined with overlay mapping technique was used to perform saline spatial predictions in the study area. The model accuracy level is evaluated based on coefficient of determination (R²) and root mean square error (RMSE). In the first stage, the values of R² and RMSE of SAR and ESP were 0.94, 0.17 and 0.94, 0.24 for ANN, and 0.35, 0.52 and 0.34, 0.76 for MLR, respectively. Similarly, in the second stage, the RMSE of ANN-Kriging were much closer to 0 and relatively lower than MLR-Kriging and Kriging. The results show that ANN-Kriging can be used to improve the accuracy of mapping and monitoring spatial distribution of saline and sodic soil in areas that develop the rice-shrimp cultivation model.     

Optimum Fertilizer Phosphorus Requirement for Maximum Productivity under Rice–Rice and Rice–Sunflower Systems in Semi-Arid Alfisols

A study was conducted at Hyderabad during 2009–11 to determine phosphorus (P) dose for rice–rice and rice–sunflower. Available P increased when 100% recommended P dose (RDP) was applied. P applied to rice gave at par yield under 100 or 75% RDP. In rice–rice, grain yield of 5668 and 5775 kg ha^?1 in kharif (5654 and 5760 kg ha^?1 in rabi) were attained with P@75 and 100% RDP. Kharif P residual effect in rabi affected rice yield. P@100/75% RDP in kharif and rabi gave grain of 5916/5973 and straw 6230/6673 kg ha^?1. P applied to sunflower revealed that yield was similar with 100 or 75% RDP. Sunflower yield was at par with P@100 or 75% RDP. 25% RDP in rice and sunflower may be reduced to attain similar yield of 100% RDP. In rice–rice, grain yield attained by 100% RDP in both seasons was 11.42t ha^?1 yr^?1, while 75% RDP gave yield of 11.45t ha^?1yr^?1.     

基于离散元的施肥机肥料块破碎装置参数的优化

为解决2BF–02型玉米全膜双垄沟扎穴施肥机作业因肥料结块而排肥不顺的问题,设计了一种由箱体和辊轮组成的肥料块破碎装置。在离散元软件EDEM中建立肥料块离散元模型,按照3因素3水平正交试验方案对肥料块破碎装置工作过程进行虚拟试验。结果表明:影响肥料块破碎率的因素由大到小依次为辊轮间距、辊轮转速、辊轮齿数。当辊轮间距为6 mm、辊轮转速为150 r/min、辊轮齿数60个时,肥料块破碎率为98.8%(最高值)。对仿真结果进行试验验证,结果肥料块破碎率为94.4%。     

钟冠报春苣苔花发育进程中花色素苷含量的变化

采用超高效液相色谱—四级杆飞行时间串联质谱联用技术（UPLC-Q-TOF-MS）测定钟冠报春苣苔（Primulina swinglei）花发育进程中花色素苷在各花器官组织中的分布、含量及比例。共鉴定出17种花色素苷类物质,分别为矢车菊素、芍药花素、飞燕草素、矮牵牛素及锦葵素及其与葡萄糖、芸香糖、乙酰芸香糖等糖苷组合而成的苷元。研究发现,呈紫色的花瓣中蓝紫色的花色素（飞燕草素、矮牵牛素及锦葵素）比例达到64.0%;呈红色的花筒中红粉色的矢车菊素及芍药花素分别占36.7%和20.0%。开花前总花色素苷含量缓慢上升并趋于稳态,该过程中红粉色的花色素占据比例逐渐减小,而蓝紫色花色素所占比例渐趋增加,这可能与花瓣/花筒的比例渐趋增大有关。而花盛开之后,花色素苷含量急剧降低,可能与花色素苷的降解或稀释相关。     

Effects of thinning on nitrogen status of a larch plantation,illustrated by 15N natural abundance and N resorption

Larch (Larix spp.) is widely distributed in the boreal and temperate areas. Nitrogen (N) is considered as the major limiting element for these areas. Thinning is a common forest management practice. Thus, it is imperative to obtain a better understanding on how thinning could affect N status of larch plantations, and thus optimize the thinning intensity for sustainable forest management. In this study, we measured N concentrations and ¹⁵N natural abundance (δ¹⁵N) of needles and surface soil (0–10?cm) in a larch plantation with T0, T25 and T50 treatments (0%, 25% and 50% thinning intensities, respectively) in Northeast China. We found that needle and soil δ¹⁵N in T25 was the lowest, and the highest in T50. No significant differences were observed for needle and soil N concentrations among the thinning intensities. T25 exhibited the highest N resorption efficiency, indicating highest N use efficiency. Overall, N cycling in T25 was more closed than the control, and with lower soil N availability, while N cycling in T50 was more opened. Our study indicates that foliar ¹⁵N natural abundance is sensitive to thinning and can be potentially used to optimize thinning intensity from the perspective of N cycling.     

Evapotranspiration and Mineral Content of Sedum kamtschaticum Fischer Under Saline Irrigation

An alternative water resource such as graywater could be used for irrigation on green roofs during hot, dry summers, although it contains salt. In this study, the response to high-salt stress of a C3–CAM (Crassulacean acid metabolism) intermediate species, Sedum kamtschaticum Fischer, was evaluated over a 2-month experiment in terms of evapotranspiration (ET) and chemical compounds in plant tissue in triplicate for both experiments. High ET (10–15 mm day^?1) was observed under non-stressed conditions. On the day following the first saline irrigation, the peak ET at noon decreased as much as one-third of the maximum. After 9 days, ET remained below 3 mm day^?1, corresponding mostly to evaporation from the wet soil surface. The balance of chemical component contents in leaves changed depending on the electrical conductivity of irrigation water electrical conductivity (EC_i). The potassium to sodium (K⁺/Na⁺) ratio, which indicates levels of sodium toxic for plant growth, decreased with higher EC_i, while it excluded sodium from roots. However, based on enhanced water use efficiency under higher EC_i regardless of reduced carbon dioxide (CO₂) assimilation under salinity stress, the plant’s method of photosynthesis shifted from C3 to CAM metabolism. These findings show that S. kamtschaticum could survive for more than 2 months under low or moderate salinity of irrigation water in hot conditions.     

Calibration of Hargreaves–Samani and Priestley–Taylor equations in estimating reference evapotranspiration in the Northwest of Iran

Accurate estimation of reference evapotranspiration (ET_o) is essential for water resources management and irrigation systems scheduling, especially in arid and semiarid regions such as Iran. In the present research, constant coefficients of Hargreaves–Samani (C_H–S) and Priestley–Taylor (C_P–T) equations were locally calibrated to estimate the ET_o based on the FAO–Penmen–Monteith (PM) method as standard method. For this purpose, meteorological data of eight synoptic stations located in the northwest of Iran were used during the period of 1997–2008. The outcomes showed that the values of C_H–S and C_P–T were 0.0026 (instead of 0.0023) and 1.68 (instead of 1.26), respectively. Also, at stations with high wind speed, the values of calibrated coefficients of C_H–S and C_P–T were maximum. Then, the estimated ET_o values using adjusted C_H–S and C_P–T coefficients were compared to the obtained actual ET_o values by PM method using root mean square error and mean bias error indices. The results indicated that the new calibrated H–S and P–T equations have good agreement with the PM method for estimation of the ET_o. Moreover, the equation of Ravazzani et al. was calibrated in the studied region. It was concluded that in general, the mentioned equation was shown better performance than original H–S equation.