施用不同配比生物炭对橡胶树根系生长的短期响应

本研究探讨施用4种用量的生物炭对橡胶根系短期的影响。结果表明:随着生物炭用量的增加,土壤有机质、全氮、速效磷、速效钾含量和pH呈增加趋势,而容重呈下降趋势;施用不同用量生物炭处理对橡胶树根重、根长、根面积和根体积的影响各异,与对照相比,生物炭低配比(1%)和高配比(10%和15%)的施用量短期内对橡胶树根鲜重、根长、根表面积和根体积均无显著影响,而施用配比含量为5%的生物炭处理短期内显著提高了橡胶树根鲜重、根长、根表面积和根体积;同时,不同施用量生物炭处理的橡胶树吸收根占总根重的比例介于64.8%~76.1%之间。综上所述,施用配比含量为5%的生物炭可在短期内显著促进橡胶根系的生长。     

Initial report of glufosinate and paraquat multiple resistance that evolved in a biotype of goosegrass (Eleusine indica) in Malaysia

Field and glasshouse studies have confirmed the presence of a glufosinate‐ and paraquat‐resistant goosegrass biotype that has infested a bitter gourd field in Air Kuning, Perak, Malaysia. Glufosinate and paraquat had been applied at least six times per year to the affected fields (originally a rubber plantation) for more than four consecutive years. Paraquat had been used since 1970 for weed control in the rubber plantation. An on‐site field trial revealed that the control of the goosegrass plants, measuring 20–35 cm in height, ranged from 20 to 35% 3 weeks after being treated with each herbicide at twice the recommended rate. Dose–response tests were conducted in the glasshouse, using seedlings at the three‐to‐four‐leaf stage that had been obtained from the plants that had received repeated exposure to these herbicides and a biotype with no history of any herbicide resistance. The comparison of the GR₅₀ (the herbicide rate that is required to reduce the shoot fresh weight by 50%) of the seedlings indicated that the resistant biotype of goosegrass is 3.4‐fold and 3.6‐fold more resistant than the susceptible biotype following treatment with glufosinate and paraquat, respectively. This study has demonstrated the world's first field‐evolved instance of multiple resistance in goosegrass to two non‐selective herbicides, glufosinate and paraquat.     

马铃薯嫁接番茄试验初报

马铃薯和番茄同属茄科植物,两者的亲缘关系较近,为探讨二者能否嫁接及嫁接后的结果情况,2009年春,用1个马铃薯品种和6个番茄品种进行异种嫁接试验。结果表明:从嫁接成活率、结果率看品种间有差异,嫁接苗普遍结薯率较低,番茄口感和生长势相对不嫁接苗普遍变差。通过试验认为番茄与马铃薯嫁接,应选用口味淡的马铃薯品种,嫁接时机应在马铃薯茎秆没有中空以前,低位嫁接为好。     

籽粒灌浆特性对小麦磨粉品质的影响及其氮肥调控效应研究

在大田条件下,以大穗型小麦品种兰考矮早8和多穗型小麦品种豫麦49-198为材料,通过设置不同氮肥施用水平,研究籽粒灌浆过程对小麦磨粉品质的影响以及氮肥的调控效应.结果表明,在各施氮处理中小麦籽粒灌浆过程均呈"S"型变化,籽粒干质量积累均可用三次曲线进行拟合,但模型参数因氮肥用量而不同.大穗型品种兰考矮早8均以N3(270 kg/hm2)处理的灌浆特征参数值较高,多穗型品种豫麦49-198以N2(180 kg/hm2)处理的灌浆持续期最长,最大灌浆速率出现的时间最晚,最大灌浆速率最高以及有效灌浆持续期最长,理论最大粒重以N0(0 kg/hm2)和N5(450 kg/hm2)处理的较高.灌浆特征参数与磨粉品质的相关分析表明,多数籽粒灌浆特征参数与磨粉品质指标之间的相关达到极显著水平;同时建立了磨粉品质指标和灌浆特征参数之间的回归方程,可以用籽粒灌浆特征参数来预测籽粒的磨粉品质.     

Comparison of Micromorphological Features of Two Agricultural Cultivated Soils in Guanzhong Areas, Shaanxi Province, China

By comparing micromorphological features of irrigated and non-irrigated soils in Guanzhong areas, China, this paper tries to illustrate the influences of farming management methods on the soil-forming process. The micromorphology was observed under a petrographic microscope and its image was quantificationally measured by Nikon NISBR 2.2 software. Both irrigated and non-irrigated soils have the same soil profile pattern, Ap1- AP2- BC, but the former has a more obvious profile dissimilation. The minerals assemblage of soil profiles A and B are very similar, which is mainly composed of Q and P1. Compared with non-irrigated soil, grains of irrigated soil remarkably decrease in length, area, eqdiameter, perimeter, elongation, roundness, and C/F10μm ratio; voids are characterized by more regular void shape and more smooth void wall; there is more abundant residual clay and small amount of illuvial clay. All results in this study suggest that the farming management method has influences on soil profile dissimilation and micromorphology. Agricultural irrigation could strengthen the degree of weathering, make smaller and rounder soil grains, cause a significant increase of residual clay and appearance of illuvial clay. But no significant change has been observed in the minerals assemblage of coarse grains.     

Crop Identification Based on TWDTW Method and Time Series GF-1 WFV

【Objective】 Yanqi Basin is an important production base of characteristic agricultural products in Xinjiang, and the planting structure of crops is complicated. In this study, the time series remote sensing data were used to classify and identify crops in the study area, so as to obtain the spatial distribution of different crops and their planting areas, which were the important basis for government sectors to formulate grain policies and economic plans. At the same time, the applicability of time-weighted dynamic time warping (TWDTW ) method in crop classification and the application potential of GF-1 WFV in agriculture were also discussed.【Method】 The normalized vegetation index (NDVI), calculated from the 2018 time series GF-1 WFV data set in Yanqi Basin, Xinjiang, was used to study the crops recognition based on TWDTW method. Sample points of different crops were collected to form standard sequence of NDVI for each crop. The TWDTW similarity matching algorithm was used to calculate the similarity distance between each pixel to be classified and the standard sequence of different crops. The smaller the distance was, the higher the similarity was. The similarity was used to determine the crop type of the pixel, and the final classification result was obtained. At the same time, the classification rules of decision tree were established according to the NDVI curve of time series, and the classification result was obtained by manually setting the classification threshold, and compared with that of the TWDTW method. 【Result】 The classification results of the two methods were very consistent. Peppers were the most widely planted and the wheat was mainly distributed in the northern part of the Yanqi Basin and the 21st Division of the Second Agricultural Division. The distributions of tomato and sugar beet were relatively sporadic. Among the results of planting area, pepper had the largest planting area, followed by tomato, wheat and sugar beet. The accuracy of the classification results of the TWDTW and decision tree methods was verified by the field sample points: The overall accuracy of them were 89.58% and 90.97%, respectively, and the kappa index of them were 0.804 and 0.830, respectively. The classification accuracy of the TWDTW method was slightly higher than that of the decision tree method. 【Conclusion】 Compared with the decision tree classification method, the classification accuracy of the TWDTW method was slightly improved, the classification result was more objective and reliable. The algorithm of TWDTW method was not limited by geographical factors and had strong flexibility and applicability. The experimental results showed that using TWDTW algorithm to identify crops based on the GF-1 WFV data set of dense temporal phase could get better classification results, and it had great application and popularization value in agricultural field.     

树皮结构与山核桃溃疡病抗性关系的研究

对树皮结构与山核桃溃疡病之间关系的研究表明,随着树龄的增大,周皮呈现出较厚的胞壁特征,病害较轻或不发病,感病指数与周皮厚度存在一定的负相关,其中,木栓层的厚度对植株抗病性的影响最大,木栓形成层区的宽度与感病指数之间呈一定的正相关,栓内层与之呈微弱的负相关。皮层的机械性能在一定程度上影响着树皮对溃疡病抗性。韧皮纤维比量在30％～50％之间,与感病指数则呈较强的负相关。次生韧皮部里的含晶纤维束占韧皮纤维总量的50％～55％,不同龄级之间差异不明显,与抗病性的相关性不明显。筛管活动能力与病害程度之间有着较强的负相关性,随着病害程度的加重,直径逐渐减小。韧皮射线组织比量与感病指数之间也呈负相关。     

水肥耦合对橡胶树根系垂直分布的影响

水分和养分是限制橡胶树生长和产胶量的重要因子.以17a树龄的热研7-33-97橡胶树为试验材料,通过田间小区试验研究了不同水肥耦合水平对橡胶树根系垂直分布特征的影响,结果表明:橡胶树吸收根系主要分布在0～20 cm土层,随土壤层次的加深,橡胶根系干重在垂直分布上呈递减趋势,可用乘幂函数模型表示.适量增施氮、磷肥均能促进0～20 cm土层根系的生长;氮肥施用量过大,深层根系比重增大;轻度降低土壤水分能够促进根系扎深.水肥耦合对根系生长和分布具有调节作用,本试验条件下,各土层根系干重总量以丰氮丰水和丰磷丰水组合处理最高,分别达0.33和0.31 kg/m3,并且根系在土壤剖面上的分布与养分分布具有一致性.     

炭基复混肥氮钾缓释特性研究

为探究生物质炭及其用量对肥料养分的缓释效果,利用实验室圆盘造粒机制备了生物质炭用量为10%、20%、30%的炭基复混肥,采用土柱模拟淋溶法研究了炭基复混肥在土壤中氮、钾淋出率。结果表明:添加生物质炭能够减少肥料氮、钾淋出量,且随着生物质炭用量的增加炭基复混肥氮、钾素累积淋出率逐渐减小。当第10次淋溶时,生物质炭用量为10%、20%、30%炭基复混肥的氮素累积淋出率分别较不添加处理减少了6.03%、12.49%、33.72%,钾素累积淋出率较不添加处理分别减少了5.15%、5.29%、13.58%,且添加30%生物质炭处理显著大于其他处理。用一级动力学方程、Elovich方程和抛物线方程对各处理养分释放曲线拟合,结果显示一级动力学方程拟合效果最好,可用于表征氮、钾素累积淋出率与时间的关系。      

Characterization of subunits encoded by SnRK1 and dissection of combinations among these subunits in sorghum (Sorghum bicolor L.)

Sucrose nonfermenting-related protein kinase 1 (SnRK1) is one of the critical serine/threonine protein kinases. It commonly mediates plant growth and development, cross-talks with metabolism processes and physiological responses to biotic or abiotic stresses. It plays a key role in distributing carbohydrates and sugar signal transporting. In the present study, eight SnRK1 coding genes were identified in sorghum (Sorghum bicolor L.) via sequences alignment, with three for α subunits (SnRK1α1 to SnRK1α3), three for β (SnRK1β1 to SnRK1β3), and one for both γ (SnRK1γ) and βγ (SnRK1βγ). These eight corresponding genes located on five chromosomes (Chr) of Chr1–3, Chr7, and Chr9 and presented collinearities to SnRK1s from maize and rice, exhibiting highly conserved domains within the same subunits from the three kinds of cereals. Expression results via qRT-PCR showed that different coding genes of SnRK1s in sorghum possessed similar expression patterns except for SnRK1α3 with a low expression level in grains and SnRK1β2 with a relatively high expression level in inflorescences. Results of subcellular localization in sorghum leaf protoplast showed that SnRK1α1/α2/α3/γ mainly located on organelles, while the rest four of SnRK1β1/β2/β3/βγ located on both membranes and some organelles. Besides, three combinations were discovered among eight SnRK1 subunits in sorghum through yeast two hybrid, including α1-β2-βγ, α2-β3-γ, and α3-β3-γ. These results provide informative references for the following functional dissection of SnRK1 subunits in sorghum.