The effects of cultivation methods and water regimes on root systems of drought-tolerant (RD6) and drought-sensitive (RD10) rice varieties of Thailand

In this study, we have attempted to investigate the effect of different water-saving cultivation techniques on root systems of two Thai rice varieties. The variables were two rice varieties (RD6 and RD10), two cultivation methods (dry direct seeding [DS] and transplanting [TP]) and two soil moisture regimes (field capacity [FC] and 50% FC). RD6 variety had higher root number, root length and root length density compared with RD10 under TP method at FC. Higher root number was observed for TP than dry DS method under FC at flowering stage with 543 and 415 roots plant^–1 for RD6 and 392 and 362 roots plant^–1 for RD10 cultivated under TP and dry DS methods, respectively. Root dry matter (DM) was the highest for RD6 cultivated through dry DS method compared with TP method at FC for both tillering and flowering stages. RD6 variety resulted in 25% and 50% higher root DM at FC for dry DS than TP at tillering and flowering stages, respectively. The performance of RD10 was poor under 50% FC and dry DS method. With proper selection of variety, dry DS method could be a better alternative for sustainable rice cultivation under water-limited environments.     

Microbial community and ovine host response varies with early and late stages of <Emphasis Type="Italic">Haemonchus contortus</Emphasis> infection

The interactions between gastric microbiota, ovine host, and Haemonchus contortus portray the ovine gastric environment as a complex ecosystem, where all factors play a pertinent role in fine-tuning each other and in haemeostasis. We delineated the impact of early and late Haemonchus infection on abomasal and ruminal microbial community, as well as the ovine host. Twelve, parasite-naive lambs were divided into four groups, 7 days post-infection (dpi) and time-matched uninfected-control groups; 50 dpi and time-matched uninfected control groups were used for the experiment. Six sheep were inoculated with 5000 H. contortus infective larvae and followed for 7 or 50 days with their corresponding uninfected-control ones. Ovine abomasal tissues were collected for histological analysis and gastric fluids were collected for PH value measurements, microbial community isolation and Illumina MiSeq platform and bioinformatic analysis. Our results showed that Haemonchus infection increased the abomasal gastric pH (P = 0.05) and resulted in necrotizing and inflammatory changes that were more severe during acute infection. Furthermore, infection increased the abomasal bacterial load and decreased the ruminal microbiome. A 7-day infection of sheep with H. contortus significantly altered approximately 98% and 94% of genera in the abomasal and ruminal bacterial profile, respectively (P = 0.04–0.05). However, the approximate altered genera 50 days after infection in the ovine abomasal and ruminal microbiome were about 62% and 69%, correspondingly (P = 0.04–0.05) with increase in some bacteria and decrease in others. Overall, these results indicate that Haemonchus infection plays a crucial role in shaping stomach microbial community composition, and diversity.     

半胱胺、四黄素和绿益康对鸡生产性能的影响

目的：本试验研究了半胱胺、四黄素和绿益康三种饲料添加剂对鸡生产性能的影响。方法：试验选取320只1日龄雏鸡,随机分成4组,每组80只,即试验Ⅰ、Ⅱ、Ⅲ组和对照组。四黄素、绿益康和半胱胺分别按0.6%添加到试验Ⅰ、Ⅱ、Ⅲ组的基础日粮中;基础日粮自配。试验期为28天。结果：饲喂半胱胺的试验组第一周平均活重比对照组提高4.27%,差异显著（p<0.05）;饲喂第二周平均重比对照组、绿益康组和四黄素组的平均活重分别提高了12.33%、11.5%和15.66%,差异都显著（p<0.05）。平均日增重提高了4.29%, 料重比降低了22.7%,育成率提高了3.8%。饲喂绿益康的试验组第一周,平均活重比对照组和四黄素组分别提高了5.04%和4.76% ,差异都显著（p<0.05）,三周后平均活重提高了3.96%,平均日增重提高了4.92%,料重比降低了15.7%,育成率提高了7.5%。饲喂四黄素的试验组平均重提高0.93%,日增重提高了4.92%,料重比下降了20%,育成率提高了7.5%。结论：本试验结果表明绿益康防病促生长效果最好。半胱胺对鸡的促生长效果最好且在饲喂半胱胺的第一、二两周后差异显著（p<0.05）,四黄素有明显的防病促生长作用。     

激素改变杂交水稻制种父本花时的试验初报

本文通过两年三点次，用１０种激素不同浓度，在父本始穗至齐穗期喷施的试验结果。初步筛选出乙稀利１０００～２０００ｐｐｍ与ＮＡＡ１００～２００ｐｍ，有一定的推迟父本花时的效应，对异交结实率不仅无影响，尚似有提高的作用，其处理后授粉结实的Ｆ１生长发育正常。     

团头鲂鱼体矿物质成分的初步分析

测定了团头鲂Ｍｅｇａｌｏｂｒａｍａａｍｂｌｙｃｅｐｈａｌａ夏花、一龄、二龄鱼种和成鱼的２０种化学元素，其在鱼体干物质中的总含量为５．２５％～８．０４％。其中约４０％分布在肌肉中，６０％分布在骨骼中。含量高的为Ｃａ、Ｐ，占２０种元素总量的７０．２９％～７８．６１％。Ｃａ：Ｐ为１：０．４７～１：Ｏ．７１。含量低于Ｃａ、Ｐ的依次为Ｋ、Ｎａ、Ｓ、Ｍｇ、Ａｌ等。随着鱼体长大，大多数化学元素相对含量减少，只有Ｋ、Ｓ、Ｐｂ的含量随之增加。     

硫酸二甲酯作为色谱法测定某些羧酸的甲酯化试剂

以苯甲酸和草酸作为不同类别酸的代表,采用硫酸二甲酯(DMS)直接和羧酸反应制得羧酸甲酯的方法,进行气相色谱分析,研究DMS与其反应生成酯的转化率和色谱条件。结果表明:在100℃,30min时苯甲酸、草酸的成酯率分别为97％和96.9％。     

Response of Wheat to Tillage Plus Rice Residue and Nitrogen Management in Rice-Wheat System

Zero tillage with residues retention and optimizing nitrogen fertilization are important strategies to improve soil quality and wheat （Triticum aestivum L.） yield in rice （Oryza sativa L.）-wheat system. Field experiments were conducted on silty clay soil （Hyperthermic, and Typic Torrilfuvents） in D. I. Khan, Pakistan, to explore the impact of six tillage methods （zero tillage straw retained （ZTsr）, ZT straw burnt （ZTsb）, reduced tillage straw incorporated （RTsi, including tiller and rotavator）, RT straw burnt （RTsb）, conventional tillage straw incorporated （CTsi, including disc plow, tiller, rotavator, and leveling operations）, CT straw burnt （CTsb）） and ifve nitrogen rates, i.e., 0, 100, 150, 200, and 250 kg ha-1 on wheat yield. Mean values for N revealed that spikes m-2, grains/spike, 1 000-grain weight （g）, and grain yield （kg ha-1） were signiifcantly higher at 200 kg N ha-1 in both the years as well as mean over years than all other treatments. Mean values for tillage revealed that ZTsr produced highest number of spikes m-2 among tillage methods. However, grains/spike, 1 000-grain weight, and grain yield were higher in tillage methods with either straw retained/incorporated than tillage methods with straw burnt. Interaction effects were signiifcant in year 1 and in mean over years regarding spikes m-2, 1 000-grain weight, total soil organic matter （SOM）, and total soil N （TSN）. ZTsr produced the most spikes m-2 and 1 000-grain weight at 200 kg N ha-1. ZTsr also produced higher SOM and TSN at 200-250 kg N ha-1 at the end of 2 yr cropping. Thus ZTsr with 200 kg N ha-1 may be an optimum and sustainable approach to enhance wheat yield and soil quality in rice-wheat system.     

Short Response of Spring Wheat to Tillage,Residue Management and Split Nitrogen Application in a Rice-Wheat System

A ifeld experiment was conducted to study the impact of tillage, crop residue management and nitrogen （N） splitting on spring wheat （Triticum aestivum L.） yield over 2 yr （2010-2012） in a rice （Oryza sativa L.）-wheat system in northwestern Pakistan. The experiment was conducted as split plot arranged in randomized complete blocks design with three replications. Treatments comprised six tillage and residue managements：zero tillage straw retained （ZTsr）, zero tillage straw burnt （ZTsb）, reduced tillage straw incorporated （RTsi）, reduced tillage straw burnt （RTsb）, conventional tillage straw incorporated （CTsi）, and conventional tillage straw burnt （CTsb） as main plots and N （200 kg ha-1） was applied as split form viz., control （no nitrogen＆no splitting, N0S0）;2 splits of total N, half at sowing and half at the 1st irrigation （i.e., 20 d after sowing （DAS）） （NS1）;3 splits of total N, 1/3 at sowing, 1/3 at the 1st irrigation, and 1/3 at the 2nd irrigation （NS2）;4 splits of total N, 1/4 at sowing, 1/4 at the 1st irrigation, 1/4 at the 2nd irrigation （45 DAS）, and 1/4 at the 3rd irrigation （70 DAS） （NS3）;and 4 splits of total N, 1/4 at the 1st irrigation, 1/4 at the 2nd irrigation, 1/4 at the 3rd irrigation, and 1/4 at the 4th irrigation （95DAS） （NS4） as sub plots. The results showed that the most pikes m-2, grains/spike, 1 000-grain weight, grain yield, and N use efifciency （NUE） were obtained at zero tillage, straw retained and 4 splits application of total N （i.e., at sowing 20, 45 and 70 d after sowing）. The results indicated that ZTsr with application of 200 kg N ha-1 in 4 equal splits viz. at sowing 20, 45 and 70 d after sowing is an appropriate strategy that enhanced wheat yield （7 436-7 634 kg ha-1） and N efifciency （28.6-29.5 kg kg-1） in rice-wheat system.