Management of nematodes and a stalk borer by increasing within-field sugarcane cultivar diversity

The aim of this study was to determine whether an increase in plant diversity could modify the structure of the nematode community in favour of less pathogenic species and whether it affected the lepidopteran stalk borer, Eldana saccharina . Four sugarcane cultivars were planted either singly or as a mixture in the furrow. Nematodes were enumerated when the crops were 6 months old for five successive 10 to 13 month old crop cycles. Results showed that the mixture of cultivars had little significant impact on the overall abundance of the plant-parasitic or free-living nematodes. However, the nematode community structure within the mixture was slightly different to that observed on any single cultivar planted on its own and there was a higher than expected proportion of Helicotylenchus dihystera during the first three crops. With successive crops and in all treatments, there was an overall trend of increasing proportions of Meloidogyne javanica in the nematode community. However, the way that the change in the species-balance occurred in the mixed cultivar plots suggested a resistance to the evolving dominance of M. javanica . These results showed that sugarcane cultivars interacted within the rhizosphere when planted in a mixture because the observed nematode community in the mixture differed from that expected. The level of damage caused by E. saccharina was slightly lower in the mixture than expected from the actual cultivar composition.     

广东水稻品种抗性与稻瘟病菌生理小种变化动态的关系

１９９１￣１９９５年对广东稻瘟病菌生理小种及部分主栽品种抗性的研究结果表明,广东稻瘟病菌小种分布及发生动态相对稳定,优势种群为ＺＢ群,ＺＣ群;优势小种为ＺＢ１３、ＺＢ５、ＺＣ１３和ＺＢ１,不同生态稻区优势小种有差异。品种间具有不同的抗性水平,本省育成推广的主栽品种对稻瘟病属中等的抗性水平,个别品种抗性偏低,属于中感至感。粳籼８９等的抗病性逐年下降,这些主栽品种抗性丧失的主要原因,一方面是原有小种的     

“中苜一号”紫花苜蓿耐盐遗传特性初步研究

以“中苜号”紫花苜蓿耐盐新品种为材料,应用ＮＣⅡ杂交试验方案,研究其耐盐遗传参数,旨在为今后苜蓿耐盐育种提供理论依据。结果表明,在直 迫下,苜蓿的干重、株高和分枝数诸性状的加性产应大于显性效应,狭义跗力较大,分别为０．４２５、０．３８７和０．４８４,具有通过选择进一步提高耐盐性的遗传潜力。     

番茄新品种‘辽粉2号’

番茄新品种‘辽粉2号’为无限生长类型一代杂种。生长势强,抗黄化曲叶病毒病、烟草花叶病毒病、叶霉病、根结线虫病等。果实扁圆形,粉红色,有绿肩,平均单果质量142 g。可溶性固形物含量4.7%。产量高,留3穗果平均产量可达109.1 t·hm~(-2)。果实口感好,硬度中等,耐贮运性好。     

青岛梅园的建设及梅花品种的搜集与选育

在简介青岛梅园这一北方“新星”后，着重报道了其在建园中完成的两项科研成果，即①梅园快速规划设计与施工；②梅花品种的搜集、整理与新品种选育     

单胚甜橙良种——梨橙的选育

梨橙是从锦橙嫁接树中选育出的大果优质单胚甜橙良种,果实倒卵形,果形指数1.08,果形整齐、端庄,平均单果质量200g,平均单果种子1.8粒,种子单胚率96%以上,果肉脆嫩化渣,多汁,微香,品质优。早实丰产,适应性强。成熟期为12月上中旬。通过对母树、无性后代的遗传稳定性鉴定表明:梨橙性状遗传稳定,既是大果优质甜橙良种,又是珍贵的育种材料。     

罐藏专用黄桃新品种‘皖83’

 ‘皖83’是从‘佛雷德里克’ ( Frederic, NJC83) 的营养系变异中选育出的罐藏专用黄桃新品种。成熟期比对照品种提早10 d, 树势中庸, 平均单果质量141.2 g, 果肉金黄, 不溶质, 果皮及果核处无红色素, 味甜酸适中, 品质优, 早果, 丰产, 适应性强, 果实加工后果肉金黄色, 有光泽, 香味浓。     

黄瓜嫁接砧木用南瓜新品种‘绿洲天使’

 ‘绿洲天使’是由引自日本的南瓜自交系‘98-6-2-1-3-1-2-2’与引自印度的南瓜自交系‘99-12-2-4-1-1-3’配制而成的黄瓜砧木用南瓜新品种。该品种嫁接亲和力好, 嫁接苗抗枯萎病能力强, 耐低温弱光能力好, 产量高, 嫁接黄瓜品质优良, 适宜全国各地日光温室、大棚及露地黄瓜嫁接栽培。     

人工草地绵羊系统优化研究Ⅲ几种冬春青绿饲料作物的引种栽培

用新西兰引进的波纳、威诺阿、帕斯加、艾品、巴堪特和当地长期种植的芜菁6种冬春青绿饲料作物在云南省种羊场2个气候带种植,对各品种生物量及干鲜比进行比较分析.结果为芜菁生物量及含水量均较引进品种高;在引进品种中,高海拔山区威诺阿表现最佳,中海拔地区艾品较好.