ORIGINAL ARTICLE: Effects of variety,sowing season and maturity stage on ruminal phosphorus release from whole maize stover and its morphological fractions

An in situ degradation technique was used to investigate the effects of variety, season and maturity stage on ruminal Phosphorus (P) release from whole maize stover and morphological fractions from five varieties of maize (conventional maize, CM; sweet maize, SM; waxy maize, WM; high oil maize, HOM; and fodder maize, FM). Maize plants were harvested in 2005, 17 and 31 days after tasselling and manually separated into leaf blade, leaf sheath, stem and husk. Results showed that the values of rapidly released P fractions (a), slowly released P fractions (b), rate constant of P release for fraction b (c) and effective disappearance (ED) of P were significantly influenced by variety, sowing season and maturity stage (p < 0.05). The ED of P in whole maize stover among the varieties decreased in the following order: FM (89.8%) > HOM (87.9%) > CM (87.0%) > SM (86.9%) > WM (83.9%). Advanced maturity stage increased (p < 0.001) the a and ED values of P in the leaf blade and leaf sheath, but decreased (p < 0.001) these parameters in the husk. The a fraction and ED of P were higher (p < 0.001) for maize sown in spring than those sown in summer. Significant (p < 0.05) interactions among variety, sowing season and maturity stage were noted in the a and ED values of P. Effective disappearance of morphological fraction varied significantly (p < 0.001) and followed the order: stem (90.3%) > leaf sheath (88.2%) > leaf blade (85.2%) > husk (84.9%). In conclusion, most of P in maize stover could be released in the rumen. The potential pollution resulting from P excretion in faeces may be alleviated, when maize stover is largely used as the main forage source of ruminants.     

园林绿化废弃物堆肥过程中碳氮养分变化规律

堆肥化处理是实现园林绿化废弃物资源化利用的有效方式。为探索堆肥化处理技术,笔者研究了在不同量物质（落叶、活性污泥、土壤）的园林废弃物堆肥中C、N含量的变化规律。试验结果表明：堆腐过程中全碳含量总体呈下降趋势,而全氮含量总体变化趋势为嗜热阶段急剧上升,低温腐熟保肥阶段增加减缓。碳氮比在堆肥化处理过程中呈下降趋势。经正交试验分析,1000 g园林废弃物中加入800 g的污泥的处理E和处理H最有利于堆肥的腐熟,得到的腐熟肥碳氮含量较为合理,其碳含量分别为413.59 g/kg和611.16 g/kg;氮含量分别为17.57 g/kg和21.95 g/kg;碳氮比为23.54和27.84。     

采收成熟度对K326烟叶内在质量和经济性状的影响

为研究不同成熟度对烤后烟叶内在品质和经济性状的影响,以元谋羊街烟区K326品种两个部位不同成熟度烟叶为材料,进行经济性状考察、化学成分检测和感官评吸。结果表明,中部成熟烟叶和上部成熟烟叶分别推迟6~7 d和8~10 d采烤经济性状最好,各项化学成分适中、协调,评吸结果表现香气量足,杂气和刺激性较小,余味舒适、干净。     

利用高温发酵菌糠研制水稻育秧基质

将经高温发酵处理后的杏鲍菇菌糠与土壤按照比例进行配比制作水稻育秧基质,分析不同配比的水稻育秧基质的理化性质,比较研究水稻秧苗的秧苗素质、根系性状和营养吸收情况等。结果表明添加高温发酵腐熟的杏鲍菇菌糠对育秧基质的容重、总孔隙度、通气孔隙和持水孔隙具有改善作用,随着菌糠添加量的增加,容重逐渐减少,总孔隙度、通气孔隙和持水孔隙逐渐增加。水稻秧苗的株高、叶绿素含量、秧苗地上部百株干重、根的百株干重、根系活力和水稻秧苗的氮、磷、钾含量水平均优于100%土壤和100%菌糠,其中V(土壤)∶V(菌糠)为20%∶80%的基质配比更有利于水稻壮秧、干物质积累、根系生长发育和对氮、磷、钾的吸收。     

早熟 优质 抗病 耐运番茄新品种冀P135和冀$136的选育

冀P135和冀S136均为无限生长类型粉红番茄杂交种,分别由自交系JBF2—2．3-M与HZF2—3．1-M、FGF2-1-3-M与HZF2-3—3-M配制而成。其中,冀P135早熟,果实正圆形,果实较硬,果皮较厚,单果重230g左右,一般产量9．00万～9．75万kg／hm^2;冀S136中早熟,果实圆形,无绿肩,外形美观,商品性好,坐果率高,单果重250g左右,一般产量9．75万～10．50万kg／hm^2。2个番茄品种均生长势中等,叶片稀疏,通风透光好,省工省时,容易管理。     

烤烟不同叶位中性香味物质分析

采用二氯甲烷同时蒸馏萃取前处理,结合毛细管GC及GC-MS技术,对许昌襄城烤烟不同叶位(8～12叶位)中性香味物质成分及含量进行了对比分析.结果表明:不同叶位适熟烟叶从第8到12叶位大部分香味物质,如二氢猕猴桃内酯、巨豆三烯酮Ⅰ、金合欢基丙酮、苯甲醇、苯乙醇、2-乙酰基吡咯、糠醛、茄酮含量呈现先升后降的趋势,到第10叶位达到最高;第10叶位各类香气物质总量最高,新植二烯、二氢猕猴桃内酯、金合欢基丙酮、2-乙酰基吡咯、茄酮等物质含量明显偏高;第12叶位中β-大马酮、巨豆三烯酮Ⅲ、香叶基丙酮、3-氧化-α-紫罗兰醇、苯甲醛含量明显偏高;第11叶位中除美拉德反应产物类香气物质总量、类西柏烷类香气物质总量外,香气物质总量、新植二烯的含量、类胡萝卜素降解产物总量、芳香族氨基酸类香气物质总量仅次于第10叶位;第8叶位中3-羟基-β-二氢大马酮、巨豆三烯酮Ⅱ含量明显偏高.     

长江中下游早籼早中熟水稻育种动态

对2004～2008年长江中下游水稻早籼早中熟组可以申报国家审定的参试品种的试验结果进行了产量及其构成、抗性和米质的初步分析。结果显示,这类品种产量持续增长的主要原因是依赖穗粒数的增加,穗数与粒重在本分析中对产量增加的贡献不大;抗病性有减弱的迹象;米质的优质率低。揭示了早籼早中熟新品种的育种动态。     

菊苣种子成熟过程中活力变化及适宜收获期

试验对盛花期后的第13天、20天、27天、34天、41天收获的黔引普那菊苣种子的标准发芽率、加速老化发芽率、发芽指数、活力指数、幼苗生长特性、电导率及脱氢酶活性进行了测定。结果:盛花期后20 d,菊苣种子发芽率最高达到82.5%,且发芽指数、活力指数、种苗芽长、脱氢酶活性都比较高,电导率比较低,此时收获的种子活力最高。在盛花期后第20~27天收获的种子,其各项指标均持续较高。因此,这段时期种子的活力较高,为收获菊苣种子的适宜时期。     

Structure and composition of the understory treelets in a non-dipterocarp forest of tropical Asia

Species richness, floristic composition, and structure of understory treelets were investigated in three 1-ha plots, distributed in the undisturbed tropical seasonal rain forest of Xishuangbanna, SW China. We investigated all the woody species except lianas in these plots, compared the differences of species diversity of trees and treelets in these plots and the differences of understory structure between this forest and the typical dipterocarp forests in SE Asia. We found 5089 individuals belonging to 356 species, 189 genera, and 63 families in the three plots. The five most important families were Rubiaceae, Euphorbiaceae, Lauraceae, Meliaceae, and Annonacae. The treelet layer was much more diverse than the tree layer, indicating that result based only on trees may be not an appropriate representation of the diversity status of a particular tropical forest type. The three plots were more similar when the treelet layer was considered than when tree layer was considered. In contrast with the dipterocarp forests in SE Asia, the understory of tropical seasonal rain forest was mainly composed of the trees with small and middle stature at maturity classes. These results indicate that the structure of tropical forest understory may differ not only among continents but also within continent.     

油茶果实含油率影响因子研究

油茶Camellia oleifera果实、种子含油率（出油率）是油茶的重要经济性状。多年多点的调查和采样分析表明,影响油茶含油率的因素有遗传品质、种子成熟度、结果数量和油茶林地的成土母质。实生繁殖的油茶林内个体之间果实、种子的含油率变异大而且相对稳定;种子充分成熟是采种的最适期;对果实及种子含油率影响最大的因子是结果多少,结果越多,含油率越低;果实发育期的气候条件与含油率之间,除个别极端干旱年度外,未见有显著相关;首次发现分布于石灰土和含钙丰富的紫砂土上油茶种子含油率相对较高,与国内外有关油料作物（树种）喜钙的结论相一致。图2表4参11