深层入渗对土壤含水率和苹果产量的影响

选取15年生开心形富士苹果,设计7个不同入渗方式处理,测定了不同处理的苹果产量和不同生育期土壤含水率。结果表明,苹果成熟前不同处理土壤含水率之间差异不明显,进入雨季以后,深层入渗技术能够将雨季降雨有效收集,并入渗到深层储存,在60～200cm,土壤含水率高出对照1%～5.22%;各处理之间苹果单株产量差异极显著,其中深层入渗技术都有增产效果,平均增产13.46%。深层入渗技术能够有效的使降雨入渗到更深层次并储存,为苹果需水临界期提供土壤水分保证,提高产量。     

Comparing RAPD and AFLPTM analysis in discrimination and estimation of genetic similarities among apple (Malus domestica Borkh.) cultivars

Forty-one apple (Malus × domestica Borkh.) cultivars were screened for RAPD (Random Amplified Polymorphic DNA) and AFLP(Amplified Fragment Length Polymorphism) markers. RAPD analysis was performed with 35 arbitrary 10-mer primers, selected from 60 primers tested (kits A, C and E, Operon Technologies, Inc.). Of a total of 362bands observed, 208 (57.5%) were polymorphic. Three-hundred-and-eighty-one AFLP fragments were obtained with 8primer combinations, of which 218 (57.2%) were polymorphic. Cultivars differentiated through mutation were included in this study and showed identical patterns when analysed with both RAPD and AFLP analysis. The estimated genetic relationships were correlated (r = 73.7%) between the analysis with the two different markers. UPGMA analysis was performed and dendrograms were constructed using either the data apart from each(RAPD and AFLP) method or combined in a single joint matrix. The relationships among the forty-one studied cultivars were basically consistent with the known lineage and geographic origins of the cultivars. The four Portuguese cultivars included in this study clustered together and diverged from the other cultivars. Apparently they constitute an independent genetic pool, which could be of interest for apple plant breeders. This revised version was published online in July 2006 with corrections to the Cover Date.     

Package protection and energy dissipation in apple packs

This paper investigates the protection afforded to apples in 3 different types of packages subjected to falling impacts. Telescopic fibreboard tray packs, plastic returnable crates and sturdy wooden boxes with varying pack-tightness were dropped from 0.5 m onto a solid concrete floor and the total bruise volume and distribution of bruising was assessed. In each case, the amount of energy absorbed was calculated from measured bruise resistance, ml J^?1. Tray packs gave the best protection with 15% of the impact energy absorbed by the fruit, followed by returnable crates with 50%, and then wooden boxes which varied from 66 to 100%.The distribution of bruising in the various layers of the packs was found to be independent of pack type. In these 5-layer packs, the average percentage of total bruising was 6 (top layer), 16, 21, 23 and 34 (bottom layer).An analysis of the energy absorbing characteristics of the tray pack cartons showed that the trays accounted for most of the energy absorption during impact. It is the stretching of the trays in 2 horizontal directions rather than tray compression at contact points that dissipates the energy.     

合阳县耕地苹果种植适宜性评价

为科学指导县域种植业布局调整,应用耕地地力评价的原理和方法,基于合阳县"测土配方施肥"项目的调查分析结果,利用"县域耕地资源管理信息系统",对本县耕地苹果的种植适宜性进行了定量评价和分级。结果表明:合阳县耕地高度适宜苹果种植的耕地有5509.99hm2,占全部耕地的6.29%;适宜苹果种植的耕地有45216.72hm2,占耕地总面积的51.62%;勉强适宜苹果种植的耕地有26301.75hm2,占耕地总面积的30.02%;不适宜苹果种植的耕地面积10574.72hm2,占耕地总面积的12.07%。最后,对合理利用各适宜性等级耕地提出了建议。     

水杨酸对新红星苹果果实乙烯合成酶的影响

0.002～5mmol/L水杨酸(Salicylicacid,SA)处理新红星苹果果肉圆片,可抑制圆片中乙烯合成酶(EFE)的活性;进一步研究表明SA处理可降低圆片中超氧阴离子(O2·)、Fe2+及Fe3+的含量,并且SA处理的果肉圆片中O2·、Fe2+及Fe3+含量水平的变化与EFE活性的变化有明显的正相关性。试验还探讨了O2·、Fe2+及Fe3+同EFE活性间的关系。研究认为SA降低O2·、Fe2+及Fe3+含量水平是它抑制EFE活性的重要原因。     

鲜切苹果保鲜技术研究进展

鲜切苹果是一种即食的新型苹果加工产品,具有方便快捷,营养价值丰富的特点,满足了现代社会快节奏生活需求,但其与未经加工的新鲜苹果相比,在贮存时更易发生品质方面的问题。阐述了引起鲜切苹果酶促褐变、水分和营养物质流失、微生物滋生以及组织软化问题的机制及国内外研究进展,并将现阶段的鲜切苹果保鲜技术从物理、化学和生物三方面进行分析总结,对其未来研究方向进行展望,旨在为鲜切苹果保鲜技术的进一步发展和应用提供参考。     

红富士苹果摘袋后着色进程与抗氧化能力的关系

为指导套袋红富士苹果根据天气适时摘袋,避免日烧,对套袋红富士苹果摘袋后着色进程与抗氧化能力的关系进行研究。结果表明,套袋红富士苹果在十月初摘袋后2d即开始有明显的花青苷积累和红色表现,清除自由基的能力也明显增强,但只有到摘袋后第3d花青苷含量大幅增加后,果实遇低温强光时才可能避免日烧。建议红富士苹果摘袋时要注意天气预报,避开3d内的霜冻。     

苹果外形特征与内在品质的典型相关分析

运用典型相关分析,研究了苹果的外形特征(面积、周长、偏心率以及似圆度等)与苹果的内在品质(水分含量、含糖量、酸度)之间的关系.结果表明:长轴与短轴比与苹果的内在特征呈正相关,而似圆度与苹果内在特征呈负相关.该研究初步为基于计算机视觉的水果实时分级提供了依据.     

考虑直径影响的苹果霉心病透射光谱修正及检测

针对苹果霉心病近红外透射光谱信息受果实直径影响的难题,提出了一种能够修正果实直径对透射光谱影响的方法。基于透射光谱采集平台获取327个红富士苹果的可见/近红外光谱(350～1 100 nm)信息,采用电子游标卡尺获取其直径(光程)信息。以直径为80 mm健康苹果的平均光谱作为参考光谱,将327个苹果的光谱与参考光谱进行比较,结合直径信息利用公式求得透射光在果实内的衰减系数P,用衰减系数P进行透射光谱的修正。修正后光谱建立支持向量机(SVM)模型、误差反向传播神经网络(BP-ANN)模型,并与修正前原始光谱建立模型进行对比。实验结果表明,应用此光谱修正方法能够显著提高模型判别精度,其中应用SVM算法对修正后的光谱建立模型效果最好,对训练集和测试集的判别准确率分别为99. 34%和90. 20%,相对于原始光谱建立的模型判别准确率分别提高了7. 84和5. 89个百分点。基于此方法修正果实直径对于透射光谱的影响是可行的,构建的模型能够实现苹果霉心病的准确判别。     

基于模糊集理论的苹果表面阴影去除方法

为了提高阴影影响下的苹果目标提取精度,该文提出了一种基于模糊集理论的苹果表面阴影去除方法。该方法将含阴影图像作为一个模糊矩阵,利用所设计的隶属函数进行图像去模糊化处理,达到图像增强的目的,进而削弱苹果表面阴影对目标分割的影响。为了验证算法的有效性,采用基于灰度阈值和基于颜色聚类2种算法对去除阴影前后的目标图像进行分割,并选用分割误差、假阳性率、假阴性率和重叠系数4项指标进行了分析比较,试验结果表明,去除阴影之后,2种分割算法所提取的苹果目标区域较去除阴影之前有了较大的提高,2种分割算法的平均分割误差分别为3.08%和3.46%,比去除阴影之前降低了20.53%和25.92%,假阳性率、假阴性率分别降低了29.79%、29.98%和21.25%、29.83%,重叠系数分别提高30.96%和24.55%。与灰度变换法去除阴影后分割的效果比较表明,该方法的平均分割误差降低了29.23%,假阳性率、假阴性率分别降低了30.97%和20.40%,重叠系数提高了26.60%;与直方图均衡化法的比较表明,分割误差降低了25.59%,假阳性率、假阴性率分别降低了22.74%和27.56%,而重叠系数提高了27.43%。这一系列数据表明,基于模糊集理论的阴影去除方法具有较好的阴影去除效果。经过去除阴影后,可以获得更高的目标分割性能,目标提取精度显著提高,表明将模糊集方法应用于苹果目标的阴影去除可以有效地提高苹果目标区域的提取精度。