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1998年从澳大利亚引入坚尼草TD58(Panicum maximum‘TD58')后,相继完成适应性评价、品种比较试验、区域试验和生产试验,2007年选育而成‘热引19号'坚尼草(P.maximum'Reyin NO.19')。结果表明:该品种年均干草产量达21753.02 kg·hm~(-2),种子年均产量为800.05 kg·hm~(-2),营养价值适中,且耐低温、耐荫、耐旱、花期晚,综合性状均优于对照品种,是适合于我国南方热带亚热带地区推广种植的牧草新品种。 相似文献
3.
蓝桉、直干桉重要材性性状的遗传参数和预期增益 总被引:1,自引:1,他引:1
在种子园育种区4个区组内,从蓝按和直干按中各抽30个家系对它们的纤维长度、木材密度的遗传力、遗传相关和遗传增益作了估算.蓝按纤维长度和木材密度的单株遗传力分别为,0.6745±0.0746和0.3546±0.1010;直干按两性状的遗传力分别为0.3416±0.1011和0.0670±0.0850.两树种的纤维长度与木材密度、树高和胸径的遗传相关系数均为正值,而木材密度与树高和胸径的遗传相关系数都是负数.为这两树种提出了选择的主要性状、选择方法和标准,还为高世代育种应注意的事项作了建议. 相似文献
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本文对30年生90株人工长白落叶松树干解析生长变异及早期预测进行了研究,结果表明,树高、胸径、材积的变异随着年龄增大而减小,14~18龄是生长变异由剧烈分化到趋向稳定的转折年龄,此时树高、胸径、材积等的幼龄至成熟龄相关达极显著水平,选择效率也处在较高水平,确定长白落叶松早期选择年龄为14年。 相似文献
6.
We examine the decision to plant trees and level of tree planting for two sites, public microdam areas and household agricultural
land, and two species groups in Tigray, Ethiopia. Both sites are not perfect substitutes, as they vary with respect to distance
from the household and tenure security. The role of permanent pooled water irrigation microdams to tree planting is important
but unknown, because water borne diseases, which may influence household income and productivity, are thought to be enhanced
by the dams. We find both disease and microdams to be important predictors to tree planting. Disease seems more important
in determining whether households plant at all, and less important in the level of planting for those that do plant. For example,
disease increases the probability of planting both eucalyptus and other species groups on household-own land, but households
suffering from malaria plant higher-cost eucalyptus trees with lower probability at both sites, while planting of other lower-cost
species increases at dam sites where other villagers can monitor the trees. We also establish a connection between planting
and agricultural residues, finding a strong substitution effect on own-land. Microdam access and age are also important. Households
living nearer to dam sites will plant both species groups there with higher probabilities, but the decision to plant on agricultural
own-land is not affected. For older dams with more developed irrigation, households are more likely to grow crops rather than
plant trees on their own land, but they plant more trees at the dam sites.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
7.
两种星天牛成虫对树种的选择试验 总被引:12,自引:1,他引:12
模拟自然界纯林和混交林食料环境,测验了黄斑星天牛和光肩星天牛成虫知97种参试树种上,栖息,取食,交配等选择行为。选拔出了一批具拒避作用的树种。 相似文献
8.
QINGuanq-hua JIANGYue-zhong QIAOYu-ling B.Nottola 《林业研究》2003,14(3):225-229
Poplar is one of the dominant tree species for the establishment of fast growing plantations in Shandong Province.Eighteen poplar clones belonging to Populus aigeiros section were introduced from Italy, Turkey and domestic regions. Populus deltoides cv. ‘Lux‘ 1-69/55 (1-69), which was widely used in Shandong Province, China, was taken as control clone (1-69).Following a randomized complete block design, seedling test and controlled afforestation trials were carried out at Juxian County,Caoxian County and Laiyang City. The results showed that the poplar clone (Populus x euramericana cv. ‘102/74‘), namely 102/74, performed well both in terms of adaptability and growth rate. The mean height of 13.9 m (H), diameter at breast height of 18.0 cm (DBH) and volume growth of 0.1445 m3 (V) were 2.2 %, 21.6% and 52.9% higher than those of 1-69 (CK), respectively,at the age of 5 years at three experimental sites. Moreover, the clone can be propagated easily and showed high resistance to poplar disease, pest as well as salinity and had longer growing period. Furthermore, wood basic density and fiber length of new poplar clone (102/74) were as same as 1-69 (CK). It was concluded that the selected clone (102/74) was ideal for the estab-lishment of fast-growing poplar plantations, especially for the pulpwood plantations in Shandong Province. 相似文献
9.
2012~2013年,对山梨园中不同品系山梨进行了果实大小、单株结果产量、石细胞含量、出汁率、可溶性固形物含量、可溶性糖含量等指标的测定和评价。结果表明:初选的12个品系22株山梨个体中,有8个品系12株山梨个体在1个或多个果实性状指标上表现比较突出。具有较好鲜食品质的有YS10-5、YS15-1、YS15-2、YS11-2;具有较好加工品质的有YS6-8、YS6-9、YS10-5、YS15-1和YS15-2;具有较高产量的有YS6-9、YS11-5、YS10-5、YS15-1、YS9-2、YS13-6、YS13-4、YS14-2、YS14-5、YS8-4和YS7-6;具有果个大且品质好的有YS10-5、YS11-2、YS11-5和YS15-1。通过模糊数学隶属函数对12个品系22株山梨个体综合评判,有6个优良品系9株优良单株果实各项指标隶属函数均值较大,从大到小依次为YS10-5、YS11YS11-5、YS9-2、YS15-1、YS14-5、YS11-2、YS6-9、YS10-2和YS15-2,其隶属函数均值范围为0.5068-0.8335。 相似文献
10.