太行山南端外来树种火炬树群落的水保效应

为了全面了解外来树种火炬树的生态服务功能,从林冠层截留量、枯落物层持水率、林地贮水性能和渗透性能4个方面,研究了6年、11年火炬树,12年刺槐、15年侧柏及荆条灌丛的水保效应。结果表明：灌层截留量：11年火炬树>15年侧柏>6年火炬树>12年刺槐>荆条灌丛,4个树种冠层截持率分别为侧柏35.89%,火炬树32.40%,荆条26.53%,刺槐3.50%;枯落物层持水率为：11年生火炬树>12年生刺槐>6年生火炬树>15年生侧柏>荆条灌丛;林地贮水性能：11年生火炬树>15年生侧柏>12年生刺槐>6年生火炬树>荆条灌丛;林地渗透性能为：11年生火炬树>15年生侧柏>12年生刺槐>荆条灌丛>6年生火炬树,在太行山低山丘陵区困难立地上,火炬树群落具有良好的水土保持作用。     

Effects of choke disease in the grass Brachypodium phoenicoides

Using phenotypic and molecular characters, as well as mating compatibility tests, the fungus causing choke disease in Brachypodium phoenicoides was identified as Epichloë typhina . A three year field experiment conducted with infected and uninfected plants of a single clone of B. phoenicoides showed no significant differences in biomass production during their vegetative growth stage, but the content of calcium, magnesium and manganese was significantly greater, and that of sodium was significantly lower in infected plants compared to uninfected plants. Infected plants produced up to twice as many reproductive tillers as healthy plants, but their reproductive tissue biomass was significantly smaller than that of healthy plants, because tiller development was arrested by choke forming stromata.     

火炬树水浸提液对玉米种子萌发的化感效应

研究了不同浓度(0.10、0.05、0.025 g/L)的火炬树(Rhus typhina)凋落叶和宿存果穗水浸提液对玉米种子萌发的化感作用.结果表明:2种器官水浸提液对玉米种子的萌发均具有强烈的抑制效应,不同浓度的水浸提液处理的种子萌发率、萌发指数和幼苗活力指数均显著低于对照,而且萌发进程延迟.凋落叶水浸提液对玉米种子萌发的化感效应强于果穗水浸提液,两者均表现出明显的浓度效应.     

Allelopathic potential of Rhus chinensis on seedling growth of radish,semen cassiae and black soyabean

The allelopathic potential of Rhus chinensis Mill on seedling growth of radish(Raphanus sativus L.),semen cassiae(seed of Cassia obtusifolia L.) and black soyabean [Glycine max(L.) Merr.] was investigated under laboratory conditions.The water extracts of seed,leaf and bark of R.chinensis inhibited the germination and the growth of roots and shoots of radish,semen cassiae,and black soyabean.Significant increasing reductions in the germination and growth of roots and shoots were observed as the concentration of water extract increased in all bioassays.The order of allelopathic potentials of the three parts from R.chinensis plant on seed germination of these receptors was leaf [ seed [ bark.However,the inhibition of water extracts from R.chinensis seed on root activity of semen cassiae was more severe than from the other two parts.The allelopathic potential on the germination of radish was higher than that of black soyabean and semen cassiae.The integrated effect index for allelopathic potential of water extracts of leaf of R.chinensis on radish,semen cassiae and black soyabean seedling growth were-0.88,-0.93 and-0.98 respectively.The results suggested that it is important to minimize the negative allelopathic potential of R.chinensis in agroforestry systems,and to exploit this traditional Chinese medicinal tree for the production of natural bio-pesticides.     

火炬树快速繁殖技术的研究初报

探讨了利用茎尖离体培养进行火炬树快速繁殖的方法,摸索了激素对试管苗增殖、生根的影响及移栽成活的技术要点.诱导芽增殖的最佳培养基是MS+BA2.0 mg/l,诱导植株生根培养基是1/2MS+IBA1.0I mg/l.     

土壤水分变异对火炬树光合作用日变化的影响

通过盆栽模拟对比试验,于2008年8月研究了城市居民区绿地、城区道路绿化带与郊区林地3种土壤条件下的水分变异对火炬树光合作用日变化规律的影响.结果表明:随着模拟的郊区林地(土壤含水量22.63％)-城市居民区绿地(14.21％)-城区道路绿化带(9.90％)的土壤水分含量变化,火炬树的光合速率日变化曲线逐渐从“单峰型”...     

环剥对火炬树克隆分株光合特性及生长状况的影响

以1a火炬树克隆分株为研究材料,采用人工环剥的方法(距地面10cm - 12cm,环剥宽度约为10cm)模拟平茬干扰处理,比较分析火炬树克隆分株的光合参数及形态生长指标的差异.结果表明:(1)环剥7d与同期对照相比,火炬树克隆分株的光合参数差异显著(P =0.042 ＜0.05),最大净光合速率下降68％,光补偿点升高129.8％,暗呼吸速率上升53.04％.(2)环剥处理7d,1a火炬树克隆分株的芽高、叶高分别降低50％和43.2％,前端水平侧根直径和后端水平侧根直径分别减少10.92％和7.96％.(3)环剥处理15d后,自环剥以上部位枝叶出现枯亡现象,而下部萌发新叶,1a火炬树克隆分株的净光合速率和表观量子效率等与同期对照相比,差异性不显著(P=0.498 ＞0.05),火炬树生理生长状况趋于正常.表明环剥对1a生火炬树克隆分株的抑制作用是暂时的.     

RNA-Seq定量分析盐肤木对铅胁迫的响应

为探究重金属污染地生态修复先锋植物——盐肤木对重金属胁迫的分子响应机制,设置3个铅胁迫水平(0、250、1000mg·kg~(-1)),应用Illumina HiSeq~(TM)2000进行盐肤木根系的转录组测序,并通过Gene Ontology(GO)与Pathway功能显著富集分析方法,分析说明盐肤木响应不同铅胁迫水平下的差异表达基因。结果表明,盐肤木在遭受轻度铅胁迫时,主要有4类水解酶与2类磷酸酶相关基因显著富集,说明盐肤木主要通过调节细胞内水解酶与磷酸酶相关基因来抵御胁迫,而在重度铅胁迫下,主要有6类氧化还原酶相关基因出现显著富集,此时氧化还原酶相关基因起到主要调节作用;盐肤木在铅胁迫下细胞受损,在轻、重度铅胁迫下,分别有24、16类细胞相关基因显著富集,但其自身可通过调节细胞内细胞器、细胞质等相关的细胞运动以应对逆境;核糖体代谢通路是盐肤木适应铅胁迫的主要代谢通路。研究表明,核糖体相关基因是盐肤木响应铅胁迫的主要应答与调节基因。     

不同立地类型火炬树人工林生物量初步研究

测定了生长在渭北黄土高原6个立地类型上的火炬树平均各器官的含水率和生物量。结果表明,各立地类型火炬树全株平均含水率为500.1～521.7g/kg,根的平均含水率为541.4～585.5g/kg,叶的平均含水率为548.3～591.7g/kg,茎枝的平均含水率最低,为410.2～419.7g/kg;不同立地类型火炬树生物量的排序为:阳坡上部(0.4308t/hm2)>峁顶(0.3195t/hm2)>阳坡下部(0.285t/hm2)>沟底(0.1478t/hm2)>阴坡上部(0.0887t/hm2)>阴坡下部(0.0626t/hm2);茎枝是火炬树生物量的主要组成部分,占全株总生物量的41.48%～60.19%,根占24.05%～37.86%,而叶仅占到13.46%～20.74%;6个立地类型上,火炬树各器官生物量以及全株生物量均表现出显著的差异性。     

植物生长调节剂对火炬树和盐肤木蒸腾耗水影响的对比研究

采用BP34000精密天平等仪器对喷施不同浓度“施丰乐”溶液(对照喷施清水)的当年生盐肤木和火炬树的实际蒸腾耗水状况进行研究,用压力室法分阶段测定了苗木的叶水势.结果表明:盐肤木属于低水势忍耐脱水耐旱树种.在干旱条件下,“施丰乐”的喷施处理能维持苗木叶水势,减少苗木的蒸腾耗水,延缓苗木干旱.盐肤木用40mg/L的“施丰乐”喷施对减少苗木潜在耗水量作用较大,火炬树则是20mg/L的处理浓度较理想.