【目的】研究不同割胶方式下不同品系幼龄橡胶树的排胶生理特性,为阐述乳管排胶机制提供理论基础,也为天然橡胶生产中针对不同品系进行合理规划割胶提供参考依据。【方法】选取PR107、RY8-79、Tjir1和RY7-33-97共4个品系的6龄未开割橡胶...【目的】研究不同割胶方式下不同品系幼龄橡胶树的排胶生理特性,为阐述乳管排胶机制提供理论基础,也为天然橡胶生产中针对不同品系进行合理规划割胶提供参考依据。【方法】选取PR107、RY8-79、Tjir1和RY7-33-97共4个品系的6龄未开割橡胶树,在S/2 d/2(割线长度为1/2茎围,每2天割1刀)的强割和后续添加1%乙烯利刺激割胶方式下,对其橡胶粒子粒径以及干胶含量、排胶体积、排胶时间、排胶初速度、堵塞指数、硫醇含量等常规排胶生理参数进行分析,并比较不同割胶刀次对这些参数的影响。【结果】(1)不同品系胶乳橡胶粒子粒径具有明显差异,起始值最大的是RY8-79和PR107,RY7-33-97的胶乳粒径较小,Tjir1的胶乳粒径最小。强割后,随着割胶刀次增加,不同品系胶乳粒径普遍短暂上升后降低,其中RY8-79和Tjir1的胶乳粒径变化较大,PR107和RY7-33-97的胶乳粒径相对稳定,但均在强割8刀后胶乳粒径降至0.80μm以下,与最大胶乳粒径之间存在显著差异(P<0.05)。乙烯利刺激后,胶乳粒径维持在较小水平。(2)干胶含量起始值最高为RY7-33-97,其次为RY8-79和PR107,最差为Tjir1。在强割条件下,RY8-79和RY7-33-97干胶含量下降较快,PR107和Tjir1干胶含量下降相对缓慢;乙烯利处理后,PR107干胶含量仅略有下降;RY8-79、RY7-33-97和Tjir1干胶含量相对下调趋势略明显,尤其是RY7-33-97。(3)强割条件下,不同品系的排胶时间和排胶体积变化规律高度一致,RY8-79排胶总体积和时间明显高于PR107、RY7-33-97和Tjir1;乙烯利处理后所有品系的排胶时间和总体积显著提高(P<0.05),其中PR107和Tjir1这2个排胶少的品系受乙烯利刺激的影响更明显。(4)强割条件下RY8-79和RY7-33-97排胶初速度明显高于PR107和Tjir1,但乙烯利刺激显著降低所有品系的排胶初速度。(5)强割条件下不同品系堵塞指数差异较大,RY8-79最低,RY7-33-97最高,乙烯利刺激明显降低该指数。(6)强割条件下RY8-79硫醇含量最高,其次为RY7-33-97、PR107,Tjir1最低,乙烯利刺激后48 h 4个品系硫醇含量均表现出降低趋势。【结论】不同品系对强割和乙烯利刺激后的排胶反应不同。强割和过度乙烯利刺激均不利于橡胶粒子粒径、干胶含量等产排胶相关参数的恢复。橡胶粒子粒径和干胶含量相对其他参数受周边环境影响较小,可作为衡量排胶是否过度的参考指标。橡胶粒子粒径0.80μm是一个较有标志性的值,胶乳粒径降到该值之下,预示应降低割胶强度。自然条件下排胶量大的品系通常不耐强割和乙烯利刺激,RY8-79和RY7-33-97作为主栽品种应尽量避免割胶中施加乙烯利,而PR107可配合施用乙烯利刺激剂。利用幼龄树,结合强割和乙烯利刺激,可以作为育种早期快速筛选不同品系是否具有耐割和耐刺激的方法之一,也为不同品系割胶制度的制定提供依据。展开更多
This paper calculates the urban, rural and general Gini coefficients （hereinafter referred to as GC） of household income in 27provinces, municipalities and autonomous regions of China between 1995 and 2010 using GC ...This paper calculates the urban, rural and general Gini coefficients （hereinafter referred to as GC） of household income in 27provinces, municipalities and autonomous regions of China between 1995 and 2010 using GC calculation formulas. After calculating the GCs, this paper analyzes their trends using density function estimation in nonparametric econometrics. The results show that the GCs of household income in provincial regions tend to rise from coastal regions to inland regions. In other words, the GCs of household income in the regions tend to rise from the east to the west and they appear to be concentrated and region-specific. A discriminate analysis of economic growth and income distribution in the provincial regions by income level and GC also shows a regional characteristic, consistent with the division of eastern, central and western China and that as one analyzes household income from the east to the west, income distribution becomes more unequal and income level becomes lower.展开更多
文摘【目的】研究不同割胶方式下不同品系幼龄橡胶树的排胶生理特性,为阐述乳管排胶机制提供理论基础,也为天然橡胶生产中针对不同品系进行合理规划割胶提供参考依据。【方法】选取PR107、RY8-79、Tjir1和RY7-33-97共4个品系的6龄未开割橡胶树,在S/2 d/2(割线长度为1/2茎围,每2天割1刀)的强割和后续添加1%乙烯利刺激割胶方式下,对其橡胶粒子粒径以及干胶含量、排胶体积、排胶时间、排胶初速度、堵塞指数、硫醇含量等常规排胶生理参数进行分析,并比较不同割胶刀次对这些参数的影响。【结果】(1)不同品系胶乳橡胶粒子粒径具有明显差异,起始值最大的是RY8-79和PR107,RY7-33-97的胶乳粒径较小,Tjir1的胶乳粒径最小。强割后,随着割胶刀次增加,不同品系胶乳粒径普遍短暂上升后降低,其中RY8-79和Tjir1的胶乳粒径变化较大,PR107和RY7-33-97的胶乳粒径相对稳定,但均在强割8刀后胶乳粒径降至0.80μm以下,与最大胶乳粒径之间存在显著差异(P<0.05)。乙烯利刺激后,胶乳粒径维持在较小水平。(2)干胶含量起始值最高为RY7-33-97,其次为RY8-79和PR107,最差为Tjir1。在强割条件下,RY8-79和RY7-33-97干胶含量下降较快,PR107和Tjir1干胶含量下降相对缓慢;乙烯利处理后,PR107干胶含量仅略有下降;RY8-79、RY7-33-97和Tjir1干胶含量相对下调趋势略明显,尤其是RY7-33-97。(3)强割条件下,不同品系的排胶时间和排胶体积变化规律高度一致,RY8-79排胶总体积和时间明显高于PR107、RY7-33-97和Tjir1;乙烯利处理后所有品系的排胶时间和总体积显著提高(P<0.05),其中PR107和Tjir1这2个排胶少的品系受乙烯利刺激的影响更明显。(4)强割条件下RY8-79和RY7-33-97排胶初速度明显高于PR107和Tjir1,但乙烯利刺激显著降低所有品系的排胶初速度。(5)强割条件下不同品系堵塞指数差异较大,RY8-79最低,RY7-33-97最高,乙烯利刺激明显降低该指数。(6)强割条件下RY8-79硫醇含量最高,其次为RY7-33-97、PR107,Tjir1最低,乙烯利刺激后48 h 4个品系硫醇含量均表现出降低趋势。【结论】不同品系对强割和乙烯利刺激后的排胶反应不同。强割和过度乙烯利刺激均不利于橡胶粒子粒径、干胶含量等产排胶相关参数的恢复。橡胶粒子粒径和干胶含量相对其他参数受周边环境影响较小,可作为衡量排胶是否过度的参考指标。橡胶粒子粒径0.80μm是一个较有标志性的值,胶乳粒径降到该值之下,预示应降低割胶强度。自然条件下排胶量大的品系通常不耐强割和乙烯利刺激,RY8-79和RY7-33-97作为主栽品种应尽量避免割胶中施加乙烯利,而PR107可配合施用乙烯利刺激剂。利用幼龄树,结合强割和乙烯利刺激,可以作为育种早期快速筛选不同品系是否具有耐割和耐刺激的方法之一,也为不同品系割胶制度的制定提供依据。
文摘This paper calculates the urban, rural and general Gini coefficients （hereinafter referred to as GC） of household income in 27provinces, municipalities and autonomous regions of China between 1995 and 2010 using GC calculation formulas. After calculating the GCs, this paper analyzes their trends using density function estimation in nonparametric econometrics. The results show that the GCs of household income in provincial regions tend to rise from coastal regions to inland regions. In other words, the GCs of household income in the regions tend to rise from the east to the west and they appear to be concentrated and region-specific. A discriminate analysis of economic growth and income distribution in the provincial regions by income level and GC also shows a regional characteristic, consistent with the division of eastern, central and western China and that as one analyzes household income from the east to the west, income distribution becomes more unequal and income level becomes lower.
