人工商品林伐区工艺设计存在问题及解决对策

针对当前人工商品林资源分布区位的重要性及采伐利用的特点,对人工商品林采伐伐区工艺设计中存在的问题进行了分析,并提出了相应的解决措施。同时,还阐明了内业计算及设计成果编写过程中需要重视的环节。     

Effects of hot water treatment on anthracnose disease in papaya fruit and its possible mechanism

Harvested papaya fruit are perishable due to rapid ripening and softening and susceptibility to biotic or abiotic stresses. Hot water treatment (HWT) can preserve fruit quality by reducing decay. The present study investigated effects of HWT on controlling fungal pathogens of papaya fruit and the possible mechanism by which HWT induced disease resistance. HWT (54 °C, 4 min) of papaya fruit had a pronounced effect on reducing the carrier rate of Colletotrichum gloeosporioides (C. gloeosporioides) in fruit peel, significantly inhibited the incidence of anthracnose and stem-end rot, effectively delayed fruit softening, but slightly promoted the rate of fruit coloring. HWT reduced the anthracnose index and fruit ripeness to a certain extent and induced changes in the wax arrangement on the surface of treated fruit, causing the wax to melt. The cracks and most stomata appeared to be partially or completely plugged by the melted wax, thereby providing a mechanical barrier against wound pathogens. HWT induced the expression of CpPGIP and promptly induced the expression of CpNPR1, and then regulated the expression of the CpPR1 gene, which may enhance the resistance of the fruit to anthracnose disease and reduce the decay rate. Together, these results confirm that HWT could reduce disease incidence and induce resistance, and thus maintain postharvest quality during storage and prolong the shelf-life of papaya fruit.     

白蜡虫泌蜡研究 Ⅱ.不同寄主植物上的泌蜡比较

本文报道了在昆明地区女贞、白蜡树和小叶女贞三种不同寄主植物上白蜡虫的泌蜡状况。试验结果表明,通过在三种寄主树上放养昆明种虫和昭通种虫,不同寄主的雄虫个体平均泌蜡量,单头种虫产蜡量因种虫和寄主不同而不同;白蜡虫在不同寄主上泌蜡存在高峰期,泌蜡高峰期因寄主和种虫不同而异;白蜡虫历时基本上不受寄主的影响,在３种寄主上大致相同。用白蜡虫雄虫个体平均泌蜡量、单头种虫产蜡量和泌蜡历时等指标衡量,在昆明地区,女贞是白蜡虫的优良寄主。     

Identification of powdery-mildew-resistance genes in common wheat (Triticum aestivum L. em. Thell.). V. Old German cultivars and cultivars released in the former GDR

A total of 59 old wheat cultivars grown in Germany prior to 1960 were tested for mildew response using a collection of 12 differential isolates of Erysiphe graminis DC f. sp. tritici Marchal (Blumeria graminis (DC) Speer f. sp. tritici). Nineteen cultivars did not possess any major resistance gene and 25 were characterized by susceptible or intermediate responses. Fifteen cultivars revealed isolate-specific response patterns that could not be attributed to known major resistance genes or gene combinations. Many of the old German cultivars inherited a mildew-resistance gene from the Canadian cultivar ‘Garnet’ which is tentatively designated M1-Ga. Cultivars ‘Bretonischer Bartweizen’ (designated M1-Br) and ‘Adlungs Alemannen’ (designated M1-Ad) appeared to carry unknown resistance genes. Among 18 winter wheat cultivars released in the former GDR. eight showed susceptibility to all isolates used. Cv. “Borenos” carries resistance gene Pm3c. Five cultivars possess gene Pm4b. two cultivars gene pm5 and one cultivar a combination of genes Pm2 and Pm4b. Cultivar ‘Zentos’ was resistant to almost all isolates used. Its resistance might be conditioned by different unknown major resistance genes.     

超高压处理对鲜切冬瓜保鲜效果的影响

【目的】研究超高压处理对鲜切冬瓜的保鲜效果,为鲜切冬瓜的保鲜提供新途径。【方法】在25℃下将鲜切冬瓜分别采用200、400和600 MPa加压处理10 min,再于4℃下贮藏9 d,以未经超高压处理为对照,每3 d测定1次鲜切冬瓜的细菌菌落总数、多酚氧化酶(PPO)活性、过氧化物酶(POD)活性、硬度和亮度。【结果】随贮藏时间的延长,鲜切冬瓜的细菌菌落总数、PPO和POD活性逐渐升高,硬度和亮度逐渐下降;贮藏至第9 d,对照冬瓜的细菌菌落总数、PPO活性、POD活性、硬度和亮度L*分别为7.17±0.13 logCFU、(120.3±1.2)%、(136.5±0.8)%、1210±69 g和32.5±0.9,而400 MPa处理的鲜切冬瓜分别为1.20±0.06 logCFU、(12.8±0.6)%、(9.2±0.5)%、2295±68 g和67.5±1.1,各项指标与对照存相比均在显著差异(P<0.05);200 MPa处理的鲜切冬瓜各项指标与对照间无显著差异(P>0.05,下同),600 MPa处理的鲜切冬瓜各项指标与400 MPa处理间也无显著差异。【结论】400 MPa以上超高压处理可杀灭鲜切冬瓜的微生物、抑制PPO和POD活性,有效保持硬度和亮度,保鲜期延长至9 d。     

贵州省甘蓝型油菜主推品种的SSR遗传多样性分析

[目的]从分子水平上了解贵州省甘蓝型油菜主推品种的遗传多样性。[方法]利用国家油菜区域试验DNA指纹鉴定使用的40对SSR引物对贵州省9个甘蓝型油菜主推品种进行多态性检测,并进行聚类分析。[结果]试验共扩增出条带191个,其中多态性条带143个,多态性比率为75%。经聚类分析,9个油菜品种被分为A、B 2簇,其中A簇包含7个品种,B簇为贵州省油料研究所选育的2个品种。A簇在相似系数0.643 4处又分为A1、A2 2个亚簇,A1亚簇为贵州省油菜研究所选育的3个品种,A2亚簇为贵州省油料研究所选育的另4个品种。[结论]同一单位选育出的品种都有更为接近的遗传背景;在该研究所用品种中,贵州省油料研究所选育的品种遗传基础相对较广,但黔油17与黔油29的遗传相似性系数达0.87,遗传基础较为相近。     

我国玉米商业育种与种子产业化初探

2012年我国玉米产量超过稻谷,成为中国第一大粮食作物。玉米在粮食生产和整个国民经济中占有日益重 要的地位。探索建立我国玉米商业化育种和种子产业化新体系,已成为我国玉米种业面对的重要课题。通 过对国内外种业发展的对比,分析了我国玉米商业化育种与种子产业化存在的问题和差距,指出了我国玉米 种业面临的机遇和挑战,提出了我国玉米种业的发展趋势。     

华南地区唐菖蒲籽球规格对其商品种球繁育的影响

唐菖蒲(Gladiolus hybridus Hort.)的商品种球通过籽球培育途径生产.为探讨籽球大小对商品种球繁育的影响,采用3个不同规格的籽球进行繁种试验.结果表明,以周径2.1～3.0 cm的籽球繁育商品球效果较好,达到商品种球规格(周径＞6 cm)的种球占所收种球的50％以上,折合每667 m2可生产15 0...     

用蚕蛹代替鱼粉饲喂蛋鸡试验

本试验旨在研究蚕蛹的饲用价值.选用同日龄罗曼商品蛋鸡90只,每组45只,分为试Ⅰ组;豆粕-进口鱼粉型日粮(2%)和试Ⅱ组;豆粕-蚕蛹型日粮(2%).两组饲料价格相同.舍内自然通风.平均温度23℃,平均相对湿度66%,日喂3次,自由采食与饮水,每日分别记录各组的采食量、产蛋量、蛋重.结果表明,鱼蚕蛹组粉日粮组产蛋率(87.9%)和产蛋重(142.38kg)高于(P<0.01)蚕蛹组(分别为87%和139.06g);但蚕蛹组第只鸡每天多收入0.017 元(P<0.01).结论认为,以经济效益来衡量,蚕蛹优于鱼粉.     

旗叶蜡质含量不同小麦近等基因系的抗旱性

于2013-2014和2014-2015年度,以多蜡质和少蜡质的4个小麦近等基因系为材料,采用田间旱棚方式控制土壤水分,研究了蜡质含量与小麦抗旱性的关系。结果表明,干旱处理后,多蜡质小麦品系旗叶的蜡质含量平均为15.15 mg g?1,较少蜡质小麦品系(8.43 mg g?1)高79.8%;多蜡质小麦品系旗叶的水势较高,干旱处理后下降幅度明显小于少蜡质小麦品系,水分散失率也显著低于少蜡质品系(P< 0.05);多蜡质小麦品系旗叶的光合速率平均下降7.5%,而少蜡质小麦品系下降9.8%;多蜡质小麦品系旗叶PSII最大光化学效率(Fv/Fm)平均下降幅度为3.4%,少蜡质小麦品系下降幅度达到5.8%;多蜡质小麦品系的籽粒产量高于少蜡质品系,平均高3.7%;多蜡质小麦品系的抗旱指数和干旱敏感指数均显著低于少蜡质小麦品系(P< 0.05)。以上结果表明,蜡质能够提高小麦的抗旱性,旗叶蜡质含量可以作为抗旱小麦品种的选择指标。