大豆植株分杈数自动提取算法研究

根据大豆植株分杈个数可以预估大豆的产量。为了满足现代农业预测农产品产量的需要,本文提出一种大豆植株分杈数自动提取算法,即首先将采集到的大豆植株图片进行灰度变换、滤波、阈值分割得到二值图像,再进行形态学中的闭运算操作得到大豆植株的轮廓,然后基于Zhang并行快速细化算法提取骨架,最后借助改进的角点检测算法对大豆植株的所有分杈点进行标记并自动统计分杈数,仿真结果与大豆植株实际分杈点一致。     

Divergent effects of defoliation intensity and frequency on tiller growth and production dynamics of Pascopyrum smithii and Hesperostipa comata

Rotational stocking theoretically enables regrazing of regrowth, but regrowth may be limited in xerophytic vegetation. We tested the hypothesis that regrowth would be slow and fixed in Hesperostipa comata (a caespitose, drought‐tolerant grass), while growth would be flexible in Pascopyrum smithii (a rhizomatous, less drought‐tolerant grass) under increasing defoliation and moisture, by assessing tiller growth rates, population dynamics and plant yield on marked plants in a Dry Mixed Grass prairie. Plots were clipped in late summer to simulate a deferred control, or intermittently during the growing season (May–August) at high intensity–low frequency (HILF), low intensity–high frequency (LIHF) or high intensity–high frequency and crossed with two water treatments (ambient and addition) in both a xeric upland and a mesic lowland. Growing season defoliation increased tiller growth rates of P. smithii in the upland, whereas HILF and LIHF reduced growth in the lowland. All defoliation regimes increased tiller growth for H. comata. Tiller populations of H. comata increased with frequent defoliation, while tiller populations of P. smithii decreased regardless of defoliation regime. Frequent defoliation, regardless of intensity, reduced yield relative to the deferred control for both grasses. While water addition consistently increased growth rates and reduced differences in tiller number among defoliation treatments, the regrowth of both grasses remained similar under varied defoliation with ambient moisture. High moisture conditions also promoted regrowth more in P. smithii compared to H. comata. In summary, neither grass species displayed an inherently fixed or flexible tiller or plant yield response in response to defoliation or moisture.     

基于知识工程的旋耕机刀辊的快速设计系统研究

为了提高旋耕机刀辊的设计效率，建立了一种基于知识工程的对旋耕机刀辊的快速设计系统：在查阅整理旋耕机刀辊设计流程及规则知识的基础上，建立刀辊参数库、规则库、实例库等知识库，选用SQL语言对知识库进行添加、查询、修改；应用基于规则和实例的混合推理方法，以SolidWorks和Visual Studio为系统开发平台，应用API二次开发工具和VB.NET语言开发刀辊的快速设计系统，实现尺寸驱动模型变更和不同农耕农艺要求下刀辊的参数化快速设计。在Intel i5处理器、系统内存8 GB配置环境下，快速设计系统运行 3~5 min即可设计出满足用户需求的刀辊CAD模型并输出文件，满足使用需求。     

Crop structure in winter oats and the effect of nitrogen on quality-related characters

The relationship between panicle structure and oat grain quality characteristics was examined in a winter oat (Avena sativa) experiment, cv. Gerald, fertilized with 80 and 200 kg/ha N. Spikelets on each whorl were counted and separated into primary, secondary, and tertiary grains, which were counted and weighed, and the kernels extracted manually and weighed. Tiller and whorl rank had relatively small effects on weight per grain and kernel content. Nitrogen application significantly increased weight per primary and secondary grain on the main stem and T1, the first tiller, while spikelet and grain numbers increased only on T1. However, weight per grain and kernel contents in all whorls on both the main stem and T1 were not significantly affected by nitrogen. Although kernel contents were significantly affected by nitrogen application on some occasions, increases and decreases were less than 2.5%. Across the whole plant, numbers of primary and secondary grains increased at the higher nitrogen application, but weight per primary grain and kernel contents were unaffected. However, weight per secondary grain significantly increased at the higher nitrogen application, thus improving uniformity of grain size which is of value to millers.     

氮胁迫条件下水稻理想株型基因ipa1对氮代谢的影响

利用水稻(Oryza sativa L.)近等基因系NIL-IPA1和NIL-ipa1,研究在施氮与不施氮条件下,理想株型调控基因ipa1在水稻快速分蘖期对氮代谢的影响。结果发现,在施氮条件下,相对于NIL-IPA1植株,NIL-ipa1水稻植株中谷氨酰胺合成酶(Glutamine synthetase,GS)、NADH谷氨酸合酶(NADH-glutamate synthase,NADH-GOGAT)的活性降低,叶片中游离氨基酸含量减少,但NADH谷氨酸脱氢酶(NADHglutamate dehydrogenase,NADH-GDH)、NAD+谷氨酸脱氢酶(NAD+-glutamate dehydrogenase,NAD+-GDH)活性升高,表明ipa1能够降低水稻植株氮素同化效率,同时提高氮素重复利用率。在不施氮条件下,NIL-IPA1和NIL-ipa1植株GS活性提高,NADH-GOGAT、NADH-GDH、NAD+-GDH活性降低,可溶性蛋白和游离氨基酸含量减少,同时发现在NIL-ipa1植株中GS、NADH-GOGAT活性变化相对较小,NAD+-GDH活性相对较低,游离氨基酸含量相对较高,表明ipa1能够降低氮胁迫对水稻植株氮同化效率的影响,提高水稻植株对低氮胁迫的抗性。     

怎样正确地使用微耕机

在广西玉林市各县区,农民使用微耕机耕作的面积逐年提高,由于大部分的农民知识水平不高,出现微耕机故障率较高,所以正确使用耕整机,注意维护和保养的误区,逐步实现机械化。     

氯虫苯甲酰胺200SC防治稻纵卷叶螟及对水稻的增产作用

【目的】研究氯虫苯甲酰胺200SC大田防治稻纵卷叶螟Cnaphalocrocis medinalis的效果及对水稻产量的影响。【方法】采用大田试验研究氯虫苯甲酰胺200SC对水稻的保叶效果及对水稻生长的影响,调查施药前后水稻卷叶株数、分蘖数、水稻叶色、千粒质量等生理指标。【结果】氯虫苯甲酰胺200SC对稻纵卷叶螟具有明显的防治效果,并能够促进水稻有效分蘖、减少无效分蘖、增加每穗粒数、提高水稻产量,但对水稻叶色、长势及结实率的影响不明显。与空白对照相比,氯虫苯甲酰胺200SC和阿维菌素18EC(阳性对照)分别可使水稻分蘖数提高24.14%和11.24%,有效分蘖数提高2.01%和3.35%,无效分蘖数减少38.06%和40.30%,每穗粒数增加10.23%和4.40%,增产12.72%和7.89%,千粒质量增加2.68%和1.86%。【结论】氯虫苯甲酰胺200SC处理对稻纵卷叶螟具有明显的防治效果,并对水稻具有增产作用,且优于对照药剂阿维菌素18EC。     

水稻突变体W33高位分蘖特性利用价值研究

为探讨水稻突变体材料W33高位分蘖特性在水稻育种上的利用价值。以野生型水稻恢复系R818及其高节位分蘖突变体W33为试验材料,用盆栽试验研究R818和W33的植株、分蘖和穗部性状差异,用大田栽培控制性试验比较R818和W33分蘖、产量构成性状及子粒产量差异,测得参试材料各性状数据。结果表明,生长前期W33和R818株高、主茎叶均长无明显差异,中后期二者株高、主茎叶均长渐显显著或极显著差异;W33单株平均分蘖数是R818的7.5~8.8倍,平均有效穗数是R818的8.6倍,分蘖平均成穗率与R818相当,但单穗穗长、枝梗数和着粒数明显低于R818,而千粒重与R818无明显差异;W33和R818单株籽粒产量均随密度增大而降低,并以最低密度条件下最高,最高密度条件下最低;尽管W33单穗产量明显低于R818,但在相同栽插密度条件下,W33和R818群体产量差异不显著(F=3.7868<F_0.05,1,4);在一定密度范围内,W33能充分发挥其旺盛的分蘖力和较高的成穗率优势,以弥补单穗产量较低的缺陷,其群体产量最终达到与R818相当的水平。说明W33旺盛的分蘖力和较高的分蘖成穗率特性在水稻育种上具有一定的利用价值。     

水稻分蘖与植株碳氮化合物含量和分蘖相关基因表达量关系分析

以分蘖特性不同的4个寒地粳稻品种和2个籼稻品种为供试材料,通过盆栽试验研究水稻分蘖发生与植株可溶性糖、全氮含量及分蘖相关基因转录表达量关系。结果表明,分蘖发生起始时间、速度及最高茎数等分蘖特性主要受遗传因素控制,穗数型品种分蘖早生快发;在分蘖过程中高分蘖品种植株可溶性糖含量和糖氮比均显著高于低分蘖品种,全氮含量与此相反;分蘖过程中高分蘖品种OsTB1、OsD3和OsD14基因转录表达量均显著低于低分蘖品种,OsMADS57基因转录表达量均显著高于低分蘖品种;分蘖发生数与分蘖不同时期植株全氮含量呈不显著负相关,与可溶性糖含量、糖氮比及OsMADS57基因转录表达量呈显著正相关,与OsTB1、OsD3、OsD14基因转录表达量呈显著负相关。