基于PTPR排名的基因随机选择算法

面对高维、小样本的基因微阵列数据,有效地提取特征基因成为一项艰巨的任务。在随机特征选择方法的基础上,引入"种子变量"及滚动的排名机制,提出一种基于职业网球选手排名(PTPR)的特征选择算法。用种子变量提高变量搜索过程的选择性,提高搜索效率,同时充分利用历史记录来动态更新种子变量,加快寻优速度。在公共数据库上的测试实验结果表明,PTPR在随机多次独立运行时得到平均50%～80%的相同基因,而MichaDraminski的方法只能保持相同基因在10%～50%左右;收敛性实验表明,PTPR的收敛速度更快且显著;而在5个数据集的独立测试集上的分类率实验表明,PTPR保持较高的分类率,如PTPR得到最高分类率大约为98%、90%、89%、95%、75%,而MichaDraminski方法的最高分类率为96%、89%、85%、95%、70%。同时,与其他典型方法相比,PTPR也得到了较高的分类率。总体上,PTPR算法具有搜索速度快、结果稳定的特点,而且在不同的分类器上都保持了较优的分类率。

Evaluation of the Production, Quality of Three Cultivars of Rhodes Grass （Chloris Gayana） and Viability of Seeds, Introduced in the Pampas

This paper describes how a research was carried out about Chloris gayana Kunth. The objective of the work was to agronomical characterize the best sowing date, establishment efficiency, first year management, persistence strategies, biomass production and seeds. The parameter evaluated was： morphological, quality and production of seeds of three commercial cultivars （Santana, Finecut and Recleimer）. Trial duration is December 2012 to December 2016 （33o S, 61o W） Argentina. Design three random blocks with three repetitions, plot 5 × 5 meter. The results were analyzed by ANOVA （Analysis of Variance）, and there was used Tukey Test （p 〈 0.05） for comparison of averages, to determine significant differences between the different ones that will be sown. It was determined that the ends of spring dates ensure better establishment. Although the data of morphology of the first year （length of pod, length of blade and number of leaves/plant） presented differences between the cv, they did not mark a tendency that ensures the best development of one. Recleimer with 598 and 1,026 accumulated degree days present the highest values in both measurements. The accumulation of biomass over the years shows that commercial cv show a very similar performance （12,000 kg DM （Dry Matter） per hectare per year）. The annual accumulation of DM would not vary significantly as monthly cuts are applied during the growing season or total accumulation without cuts would be allowed. In relation to quality parameters （gross protein, neutral detergent fiber and acid detergent fiber）, Recleimer has the lowest values. Santana and Finecut were best in quality. Production of the seed was highest in May for all cvs. However, viability was limited in all date but Finecut and Recleimer showed best performance. As expected, in the megathermal species, seed production being one of the critical points.

Variability of Phytic Acid and Inorganic Phosphorus Contents in Seeds of Tropical Maize （Zea mays L.）

The correlation coefficients and scattering were studied in Ki and new inbred lines for phytic acid （PA） and inorganic phosphorus content （InP） content in seeds of tropical maize （Zea mays L.）. The understanding of the variability in PA and InP characters would be useful in a breeding program. A total of 16 Ki and 25 new inbred lines of tropical maize were planted in Completely Randomized Design （CRD） during late rainy season, 2007 to early rainy season, 2009 at Inseechandrastitya Institute for Crops Research and Development, Thailand. The result showed low correlation with no statistical significant between PA and InP contents in corn seeds performed either in different sources of inbred lines or years. For PA content, most of inbred lines were skewed toward high PA （〉 900 mg/100 g） both in Ki and new inbred lines in every year. The lowest PA value found in Ki inbred lines both in two years were Ki10, Ki15, Ki20, and Ki52.30A10-S11-43-1-3 was the lowest PA inbred lines observing in two years in new germplasm.