Absorption and fate of imazapyr in leafy spurge (Euphorbia esula)

Imazapyr absorption, translocation, root release and metabolism were examined in leafy spurge (Euphorbia esula L.). Leafy spurge plants were propagated from root cuttings and [¹⁴C]imazapyr was applied to growth-chambergrown plants in a water + 28% urea ammonium nitrate + nonionic surfactant solution (98.75 + 1 + 0.25 by volume). Plants were harvested two and eight days after herbicide treatment (DAT) and divided into: treated leaf, stem and leaves above treated leaf, stem and leaves below the treated leaf, crown, root, dormant and elongated adventitious shoot buds. Imazapyr absorption increased from 62.5% 2 DAT to 80.0% 8 DAT. Herbicide translocation out of the treated leaf and accumulation in roots and adventitious shoot buds was apparent 2 DAT. By the end of the eight-day translocation period only 14% of applied ¹⁴C remained in the treated leaf, while 17% had translocated into the root system. Elongated and dormant adventitious shoot buds accumulated 3.2- and 1.8-fold more ¹⁴C, respectively, 8 DAT than did root tissue based on Bq g^?1 dry weight. Root release of ¹⁴C was evident 2 DAT, and by 8 DAT 19.4% of the ¹⁴C reaching the root system was released into the rooting medium. There was no metabolism of imazapyr in crown, root or adventitious shoot buds 2 DAT; however, imazapyr metabolism was evident in the treated leaf 2 and 8 DAT. Imazapyr phytotoxicity to leafy spurge appears to result from high imazapyr absorption, translocation to underground meristematic areas (roots and adventitious shoot buds), and a slow rate of metabolism.     

稚蚕人工饲料中桑绿枝粉的添加效果及加工特点

在家蚕稚蚕人工饲料中分别添加 15 %的桑绿枝粉、冬桑条粉、桑皮粉等 ,并与豆腐渣、市售纤维素粉末等进行了对照试验 ,结果以添加桑绿枝粉的稚蚕人工饲料各项成绩最为理想 ,稚蚕对其有良好的摄食性 ,从而为研制稚蚕低成本人工饲料开辟了新的原料来源     

三倍体梨新品种‘龙园洋红’

 龙园洋红’是三倍体梨新品种, 属短枝型, 亲本为56-5-20和乔玛, 抗寒力强, 平均单果质量185.5 g, 最大可达650.6 g, 果实为不规则长椭圆形, 果型指数1.13。果皮底色黄, 有红晕。果肉白色,细软多汁, 可溶性固形物16.05% , 可溶性糖11.68%。可滴定酸0.81% , 果实9月15日左右成熟, 风味酸甜适度、有香味。     

苹果新品种‘天汪1号’

 ‘天汪1号’是从‘红星’的芽变中选育出的苹果短枝型新品种, 在天水地区9月中旬成熟,果实生育期148 d。果实圆锥形, 五棱突起, 果形指数0.90～0.98, 平均单果质量210 g, 果实全面浓红,色相片红; 果肉细而致密, 汁多, 味香甜, 可溶性固形物含量11.9%～14.1%。树势强健, 丰产, 稳产。     

Simulating the cumulative effects of multiple forest management strategies on landscape measures of forest sustainability

While the cumulative effects of the actions of multiple owners have long been recognized as critically relevant to efforts to maintain sustainable forests at the landscape scale, few studies have addressed these effects. We used the HARVEST timber harvest simulator to predict the cumulative effects of four owner groups (two paper companies, a state forest and non-industrial private owners) with different management objectives on landscape pattern in an upper Michigan landscape managed primarily for timber production. We quantified trends in landscape pattern metrics that were linked to Montreal Process indicators of forest sustainability, and used a simple wildlife habitat model to project habitat trends. Our results showed that most trends were considered favorable for forest sustainability, but that some were not. The proportion of all age classes and some forest types moved closer to presettlement conditions. The trend for the size of uneven-aged patches was essentially flat while the average size of patches of the oldest and youngest age classes increased and the size of patches of the remaining age classes decreased. Forest fragmentation generally declined, but edge density of age classes increased. Late seral forest habitat increased while early successional habitat declined. The owners use different management systems that cumulatively produce a diversity of habitats. Our approach provides a tool to evaluate such cumulative effects on other landscapes owned by multiple owners. The approach holds promise for helping landowner groups develop and evaluate cooperative strategies to improve landscape patterns for forest sustainability.     

临安市竹笋加工业持续发展对策初探

分析了临安市发展竹笋加工业的优势及存在的问题，提出促进其持续发展的对策。     

混交林纯林中毛竹出笋退笋特性研究

应用出笋量的逻辑斯谛 ( L ogistic)模型研究了出笋量随时间增长的变化规律 ,结果表明 :出笋前期 (前 1 0 d)出笋数占总数的 1 5%左右 ,出笋中期 (第 1 0～ 2 0天 )占 75%,出笋末期 (第2 0天以后 )占 1 0 %;对退笋特征的观察及其规律的研究得出 :出笋前后期退笋数量少但退笋率高 ,而出笋中期退笋数量多但退笋率低 .小于 1 0 cm的浅鞭竹笋多属退化笋 .纯林中的出笋比混交林中的出笋持续天数短 ,退笋率高 ,为此混交林更有利于竹笋的生长 .出笋退笋规律可用来指导生产 ,为留养和挖取竹笋数量提供依据     

添加麸皮与纤维素酶对笋壳青贮后氰甙含量的影响

[目的]研究添加麸皮与纤维素酶对笋壳青贮后氰甙含量的影响。[方法]采用异烟酸—吡唑啉酮比色法研究添加麸皮与纤维素酶对笋壳青贮后氰甙含量的影响。[结果]添加麸皮与纤维素酶均可降低笋壳青贮后的氰甙含量。麸皮添加水平越高,青贮笋壳毒性越低,当麸皮添加水平为15%时笋壳青贮后氰甙含量最低。[结论]该研究可为笋壳饲料的资源化利用提供理论依据。     

Effects of Soil Temperature on Growth and Root Function in Rice

Abstract

The objective of this study was to clarify the effects of soil temperature in the stage from late tillering to panicle initiation (SI) and during the grain-filling stage (SII) on grain setting, dry matter production, photosynthesis, non-structural carbohydrate (NSC), xylem exudation and abscisic acid (ABA) levels in rice (Oryza sativa L. cv. Koshihikari). Rice plants were exposed to four different soil temperatures during SI or SII: 17.5, 25, 31.5 and 36.5°C (ST18, ST25, ST32 and ST37, respectively). The yield, yield components, grain filling and quality in SI were negatively influenced by high soil temperature of 37°C. On the other hand, there was no significant difference in those characters among temperature treatments in SII. The root/shoot ratio was smallest in the ST37 plants in both SI and SII, mainly due to their lighter root weight. At 7 days after initiation of treatment (DAT) in both SI and SII, the photosynthetic and xylem exudation rate tended to increase slightly as soil temperature increased up to 32°C. At 21 DAT, however, the photosynthetic rate was lowest in ST37, with concurrent decrease of diffusion conductance and SPAD value. In addition, decrease of NSC concentration in stem and xylem exudation rate, and increase of ABA level in leaves and xylem exudate were observed in ST37 plants at 21 DAT. These results suggested that high soil temperature before heading especially influenced yield, grain quality and plant growth. Possible mechanisms of the effect of soil temperature are discussed.     

增产菌对复种燕麦产草量影响的试验

采用拌种、喷洒和拌种+喷洒3种方法,对临夏县北塬灌区麦后复种燕麦草增产效果进行了初步研究。结果 表明,增产菌对麦后复种燕麦的增产效果极显著(p<0.01),最佳拌种量300 g/hm2,最佳喷洒量300 g/hm2,最佳处 理组合为300 g/hm2拌种+300 g/hm2喷洒。