不同氮磷配比对旱作土壤养分和油葵产量的影响

采用调查分析、田间试验等方法,研究了旱作土壤条件下油用向日葵氮磷肥的吸肥特性和对氮磷肥的吸收规律。结果表明:不同厚度(0～20cm)和(20～40cm)的土壤对养分的吸收呈现动态的变化特点,施氮270.0kg/hm2时吸收氮素分别为47.5和35.7mg/kg,相差24.8%;油葵产量为2 604.0kg/hm2,施磷100.05kg/hm2时吸收磷素分别为28.4和21.5mg/kg,相差24.2%,油葵产量为3 199.5kg/hm2。     

福建省水稻霜霉病诊断和病原鉴定

水稻霜霉病诊断特征为植株矮缩,叶片黄化、产生黄褐色条斑.利用显微镜检查染色病组织内的病原菌藏卵器和卵孢子,通过观察病原菌的培养性状、形态特征和致病性测定,该病原菌被鉴定为大孢指疫霉水稻变种.     

中稻高产施肥技术

综述了中稻高产施肥的关键技术,包括秧田合理施肥、大田施足基肥、科学安排大田各生育阶段施肥比例、看苗巧施穗粒肥等内容,以期指导中稻的合理施肥。     

不同杀菌剂对采后柑橘绿霉病的防治效果比较

本文报道先刺伤接种柑橘绿霉病菌（Penicillium digitatum）孢子悬浮液，再进行不同类型、不同浓度药剂对抗苯并咪唑类和咪唑类杀菌剂（双抗）或双敏感菌系的防治效果。结果表明：500 、1000mg/L甲基硫菌灵、咪鲜胺和抑霉唑（500mg/L）单剂，或500mg/L甲基硫菌灵和咪鲜胺混剂对双抗菌系防治作用均低于50%。而1000mg/L百可得，500、1000mg/L百可得与相同浓度咪鲜胺均可控制双抗菌系引起的腐烂。1000mg/L咯菌腈防效为83.33%，500、1000mg/L嘧霉胺防效分别为91.11%、98.89%。500mg/L百可得、抑霉唑和嘧霉胺单剂，500mg/L百可得和相同浓度咪鲜胺混配，500mg/L甲基硫菌灵和相同浓度咪鲜胺混配对敏感菌系均有89%以上防效。基于研究结果，建议不再使用苯并咪唑类和咪唑类杀菌剂单剂，或这两类杀菌剂混剂防治柑橘采后病害，可选择1000mg /L百可得单剂，500mg /L百可得和相同浓度咪唑类混剂，同时建议将嘧霉胺登记用于柑橘采后处理。     

优质籼型水稻光温敏核不育系万金S的选育

万金S是广东海洋大学农学院利用扬稻6号(9311)的育性变异单株育成的水稻光温敏核不育系,于2009年9月通过广东省技术鉴定。万金S不育期间败育彻底,不育性稳定,不育株率100%,花粉不育度和套袋自交不实率均为99.99%;不育起点温度较低(23～24℃),在湛江不育期135 d以上;开花习性好,异交结实率高达60%以上;米质优,达国标《优质稻谷》2级标准;所配组合杂种优势强,稻米品质优,其中万两优香1号于2011年6月通过了海南省品种审定。     

Measurement variability in soybean water status and soil‐nutrient extraction in a row spacing study in the U.S. southeastern coastal plain

Abstract

Full‐season determinate soybean [Glycine max (L.) Merrill] was grown in the field in a humid climate for three seasons (1979–81). The objective was to examine variability in several methods of determining basic relationships between soil and plant water status in a range of canopy configurations and to examine treatment effects on soil‐nutrient extraction. In each year, two cultivars, “Davis” (group VI) and “Coker 338” (group VIII) were planted in four row spacings. In 1980 and 1981 the experiment was expanded and split for irrigation and row orientation (N—S or E‐W). Post‐harvest soil samples were collected and analyzed to determine if irrigation, row spacing, or cultivar influenced K, Ca, and Mg extraction patterns.

During the growing seasons, parallel leaf diffusive resistance (R_s) was poorly correlated with xylem pressure potential (ψ_x), canopy s x temperature (T_c), canopy minus air temperature (?T), leaf vapor pressure deficit (LVPD), and atmospheric vapor pressure deficit (VPD) in single factor correlations. Xylem pressure potential was highly correlated with T_c , ?T, VPD, and LVPD, but was poorly correlated with soil water potential. Both ψ_x and T_c were significantly affected by the imposition of shade from a 60% shading cloth within as little as 1 minute of shade imposition. The impact of cultivar on seasonal ψ_x was significant and was nearly half the magnitude of the observed difference caused by irrigation. Irrigation raised ψ_x by only 2.2 bars over the two—year observation period, in spite of large differences in soil water potential when irrigation was imposed. The impact of canopy configuration was not measureable in any water relations parameter except infrared‐determined T_c. Correlation of T and ψ_x was significantly more reliable when limited to a single variety, row spacing, and row orientation. Aspect of infrared temperature measurement also significantly affected observed T_c.

Analysis of post‐harvest soil samples indicated that narrow (50 cm) row spacing in 1980 and irrigation in 1981 significantly decreased post—harvest Mehlich No. I extractable K, but none of the cultural practices influenced extractable Ca or Mg at P(0.05). In 1980, ex‐tractable K within soybean rows was significantly greater than between rows. Similar trends were observed for Ca and Mg in 1980 and for all 3 nutrients in 1981, but those differences were not significant at P(0.05). Overall, these measurements quantify the difficulty in relating soil and plant water status and identifying nutrient extraction patterns in sandy soils within the humid U.S. Southeastern Coastal Plain.     

大豆脂肪酸含量的QTL分析

利用Charleston(♀)×东农594(♂)的F14和F15代永久自交系群体154个单株后代,在2年3点条件下用气相色谱法测得其籽粒5种脂肪酸的含量,利用Win QTL Cartographer2.5复合区间作图法(CIM)进行QTL分析。结果共检测到47个相关的QTL,分布在13个连锁群上。多年多点同时检测到的QTL共有15个,其中控制软脂酸性状的2个,包括qPal-C2-2和qPal-A1-1;控制硬脂酸性状的4个,包括qSt-B1-1、qSt-B1-2、qSt-D1a-1和qSt-C2-1;控制油酸性状的3个,包括qOle-B2-1、qOle-G-1和qOle-H-1;控制亚油酸性状的有2个,包括qLin-C2-1和qLin-H-1;控制亚麻酸性状的4个,包括qLino-B1-1、qLino-C2-1、qLino-D1b-1和qLino-J-1。这些QTL的一致性较高,为特异脂肪酸含量标记辅助育种奠定了基础。大豆脂肪酸含量的主效QTL数量不多,效应大的不多,可能还受许多未能检测出来的微效基因控制。     

FLOODING STRESS: The Effects of Planting Pattern and Water Regime on Root Morphology,Physiology and Grain Yield of Rice

Field experiments were conducted over two growing seasons to investigate the effects of variations in water regime and planting pattern on the growth of rice plant roots and shoots and on yield. Four water regimes were evaluated with split plot design: intermittent flooding during the vegetative stage only (IF‐V); intermittent flooding extending into the reproductive stage (IF‐R); not flooded (NF); and continuously flooded (CF), interacting with three different planting patterns: single seedling per hill with wider 30 × 30 cm spacing (P1); single seedling per hill with closer 20 × 20 cm spacing (P2); and three to four seedlings per hill with 20 × 20 cm spacing (P3). The treatment combination CF/P3 corresponds most closely with current conventional practice. The other combinations were evaluated to contribute to a better understanding of the effects of the two parameters studied, respectively and together. IF‐V/P1 was considered as an approximation of System of Rice Intensification (SRI) practice. This study found that the combination of singly transplanted seedlings, both P1 and P2, with the IF‐V water regime improved root length density, root physiological activity, and chlorophyll content of the upper and lower leaves, leading to higher grain yield compared with the other treatment combinations. With continuous flooding (CF), P2 gave 23 % more yield compared with the P3 planting pattern. Combining IF‐V and P2 produced 32 % more grain yield compared with the CF/P3 treatment. These results showed a synergistic effect on grain yield from reduced intra‐hill competition and IF‐V water management. In these trials, there was no significant yield difference between the IF‐V/P1 and CF/P3 treatments. Wider spacing improved the performance of individual hills when grown under IF‐V water regimes, but tiller number per unit area remained a dominant determinant of yield. The yield reduction observed for CF/P1 compared with CF/P3 indicated that in more hypoxic CF soils, denser plant populations can produce more than sparser ones, whereas the latter benefit from more aerobic soil conditions. Intermittent irrigation during the vegetative growth stage and transplanting single seedlings/hill are major elements of SRI methodology. These findings contribute to an understanding of why SRI methods can produce the higher yields reported. A consideration of the effects of interaction between planting pattern and water regime shows the need to establish empirically the optimum values for these treatments according to varietal, soil and climatic characteristics for the greatest yield response.     

The Prospects of Tissue Culture and Genetic Engineering for Strawberry Improvement

Abstract

Strawberry shoot meristem cultures have been used for producing virus-free strawberry plants. Plantlet regneration from leaf mesophyll protoplasts, and Agrobacterium tumefaciens mediated genetic transformation, mark the beginning of strawberry improvement with biotechnologies. The use of biotechnological tools has a greater potential in producing strawberry plants with traits such as early maturation, frost and disease resistance, mite and nematode resistance, high yield, better quality, suitability for mechanical harvesting, shipping ability, ellgaic acid content, aroma compounds and cost-effective micropropagation. Gene identification and mapping with RFLPs or RAPDs would be desirable. Transgenic strawberries should be tested for their quality before releasing to the consumers.     

新型双足攀爬机器人夹持器模块的改型设计

文章详细设计和分析了一种应用于新型双足攀爬机器人Climbot的夹持器及其改型设计成果。由于原有夹持器存在诸多缺陷,例如结构复杂、可靠性低、加工工序复杂、制造成本高昂等。同时夹持器所属攀爬机器人的远景目标则是大规模推广应用,因此,设计制造一种结构简单、稳定可靠且成本低廉的夹持器成为当下的一个重要任务。针对这个现实需求,我们对原有夹持器进行了多次试验和深入分析,找出其中的不足,并对存在的问题提出多种解决方案。我们设计出一款新式夹持器,该夹持器结构简单,加工方便,而且部分关键零部件实现了标准化,成本得到了进一步降低。同时,在减轻夹持器重量的同时,通过结构的优化和材料选择,保证了夹持器应有的结构强度和刚度,满足设计要求。