绿色农业发展背景下的农作物品种改良策略研究

随着人口增长和经济发展,全球粮食需求不断增加,农业生产面临着日益严峻的挑战,绿色农业已成为全球关注的焦点。传统农业生产模式存在诸多问题,如土地资源利用效率低、农药和化肥滥用导致环境污染、气候变化对农业生产的不利影响等,这些问题迫切需要解决。农作物品种改良作为提高粮食产量、品质和抗逆性,以及保护生态环境的关键手段,受到广泛关注。在绿色农业理念的指导下,农作物品种改良不仅要追求产量增加,也要注重环境友好性、资源节约和气候适应性,以实现农业的可持续发展。本文深入分析了农作物品种改良的现状与挑战,探讨了绿色农业发展背景下的农作物品种改良策略,对不同品种改良策略的比较研究和前瞻性分析,以期为农业科研机构、相关管理部门和农业生产者提供科学依据和决策参考,推动农作物品种改良技术的应用和推广,为促进农业现代化发展、推动农业可持续发展提供理论指导和实践支持。

基于近红外光谱法的精米品种判别优化研究

由于地理标志性大米巨大的市场价值,导致掺假行为时有发生。因此,为保证地理标志性大米品牌效益和消费者权益,实现准确的精米品种判别具有重要意义。近红外光谱法是精米品种判别的常用方法,通过提取不同品种近红外光谱中的差异性特征实现品种分类。然而,现有研究中存在特征波长选取性能不足和针对指定品种判别准确度不足的问题,限制了基于近红外光谱法的精米品种判别准确度的提升。针对上述问题,面向东北地区五常、响水、越光、银水四种大米,从特征波长选取和品种判别策略两个方面,研究基于近红外光谱法的精米品种判别优化。首先,为提高特征波长选取性能,将排列熵和自适应滑动窗口分割相结合,提出了基于自适应滑动排列熵的精米光谱特征波长选取方法,并开展与传统特征波长选取算法的对比实验。其次,为提高面向不同指定品种的判别准确度,提出基于判别目标的精米品种判别策略,通过研究光谱预处理算法与分类建模算法匹配优化,建立“指定品种-选定模型-选定算法的”的判别流程。实验结果表明,采用所提出的自适应滑动排列熵算法进行特征波长选取,相比于传统算法精米品种判别误差至少可降低50%;采用所提出的基于判别目标的精米品种判别策略,相比于传统的基于固定模型的判别策略的判别准确度至少可提高2.5%。

中国小麦品种抗条锈病现状及存在问题与对策

小麦条锈病是小麦重大病害,利用抗病品种是防治小麦条锈病的有效措施。新中国成立以来,中国科学家们广泛开展了小麦条锈病防控方面的研究,并取得显著成绩。大量抗源被筛选、鉴定,但由于抗源自身农艺性状差等原因,能应用于小麦育种的抗源亲本非常少,抗源利用不合理,导致生产品种抗病基因单一,病原菌流行小种很快形成,抗病品种在生产上可利用的寿命太短。本文介绍了国内外抗条锈病基因发掘情况,以及我国小麦抗条锈病育种抗病基因使用概况,通过回述1B/1R(Yr9)和Yr24/Yr26抗源的兴衰周期,总结了抗源利用的教训和经验,探讨了我国小麦抗条锈病育种中存在的问题和今后抗病基因合理利用的发展方向。

供应链管理中订货策略的比较与分析

对Sunil Chopra和Peter Meindl提出的多品种商品订货策略作了进一步探讨,通过对库存成本的比较分析,证明了在一定条件下统一订货策略并不优子单独订货策略,从而修正了Sunil Chopra所得出的结论。

北京信贷市场的现状与商业银行的竞争策略研究

研究商业银行在北京的信贷业务竞争策略首先要分析信贷目标行业的价值创造能力,从而确定信贷目标行业的范围。传统经济学对行业的分析强调依赖GDP增长率、资产收益率等绩效指标,其实质都是会计利润,而不是经济利润。本文对商业银行信贷目标行业的分析引入了一种新型的公司业绩衡量指标——经济增加值,它克服了传统指标的缺陷,能更准确地衡量信贷目标行业的价值创造能力,对其分析可总结出商业银行可以进入的信贷行业群为房地产行业群、基础行业群、高技术行业群和文化行业群。最后,本文在理论和实证分析的基础上,提出了商业银行的整体竞争策略、品种竞争策略和行业竞争策略。

Breeding of New Maize Variety ‘Wan-de No.1' with High Quality, High Yield and Multi-resistance

Considering the ecological environment of Sichuan area, an experiment was conducted to breed new maize varieties with high yield, high quality, multi re- sistance and wide adaptability. According to the principle of gene recombination, the authors combined the local tropical germplasm with PB germplasm, which was rich in disease-resistant, lodging-resistant and drought-tolerant genes, and the integration was used as the innovative strategy for breeding. Inbred-line ＇LSC 107＇ was suc- cessfully bred and the new maize hybrid ＇Wande No.l＇ was bred by crossing ＇LSC 107＇ with ＇Yi 99-19＇. The results showed that the maize hybrid had good performance, including high yield, good stability, high quality, excellent disease re- sistance and lodging resistance, and wide adaptation. So it was adaptable for plant- ing in plain and hilly areas of Sichuan Province. With hybrid recombination between local tropical germplasm and PB inbred lines, the inbred-line had high general com- bining ability and strong adaptability, and the hybrid had high yield, high quality and wide adaptability, and had broad prospects of popularization and application.

小榕树造就大品牌

尽营亚洲旅游业困难重重,但是超豪华的连锁酒店——悦榕度假酒店却找到了增加收入,巩固品牌的独特方法。现在它又要准备继续快速扩张开着手准备上市工作。

The Role of Habitat Manipulation in the Bio-control of African Rice Gall Midge, Orseolia oryzivora Harris and Gagne （Diptera： Cecidomyiidae） in Nigeria

Field experiments were conducted at two key locations in two successive seasons in Nigeria to determine the role of habitat manipulation in the bio-control of African rice gall midge, Orseolia oryzivora using Platygaster diplosisae an endoparasitoid of the midge. The habitat manipulation strategy tested in the study was to plant seedlings ofPaspalum scrobiculatum on one meter strip of land at the border of each rice plot early in the cropping season to conserve P. diplosisae in its alternative host, Orseolia bonzii that infest P. scrobiculatum. The Paspalum seedlings were allowed to be fully established, infested naturally by 0. bonzii and parasitized by P. diplosisae before transplanting rice varieties in each plot. The control plots were planted with only rice seedlings leaving the border empty without any Paspalum. Rice plots with Paspalum at the edge had much lower levels of O. oryzivora infestation than the control plots. The percentage number of gall midge parasitized by P. diplosisae showed that rice plots with Paspalum at the edge had more parasitized galls than the control plots without Paspalum. The role of the Paspalum border was substantiated with the negative correlation results recorded with the infestation indicating significant decrease in the percentage tiller infestation as the percentage parasitism increased. That resulted in higher grain yield in the plots surrounded with Paspalum treatment than in the control. The present study therefore demonstrated that management of P. scrobiculatum on a strip of land around the edge of rice crops could significantly increase parasitoid carry-over into the crop.

农户财富水平对种植品种多样化行为的影响分析

本文通过对黑、吉、蒙3省232个调查样本的数据分析,发现有38.8%的农户采用品种多样化策略。种植单一作物的农户更愿意采用品种多样化策略,有81%的农户采用了多个品种;通过对影响农户品种多样化策略的因素进行分析发现,农户的财富水平与多样化策略之间存在倒U型关系;在家庭财富水平指标中只有固定性资产对多样化策略影响显著。