Photosynthetic Light Utilization Efficiency, Water Relations and Leaf Growth of C3 and CAM Tropical Orchids under Natural Conditions

Native orchid species of Singapore in their natural conditions experience stress from high irradiance, high temperatures and periods of extended low rainfall, which impact orchid plant physiology and lead to reduced growth and productivity. In this study, it was found that there was a reduction in photochemical efficiency of photosystem II (PSII) in 6 native orchid species under high light (HL) and Bulbophyllum membranaceum under low light (LL). There was chronic photoinhibition in these 6 orchid species over a period of 3 months after transplanting onto the tree trunks without watering and fertilization, especially in Coelogynes mayeriana and Bulbophyllum membranaceum under both HL and LL. This chronic photoinhibition caused by sustained period of water deficit in their natural conditions was later reversed by natural re-watering conditions from higher rainfall. These results indicate that water deficit has a greater impact on photosynthetic light utilization efficiency than excess light. The present study also showed that after natural rewatering, relative water content (RWC) of leaves and pseudobulbs generally increased. During the natural re-watering, total leaf area also gradually increased and reached maximum expansion after 7 weeks under both HL and LL, with some exceptions due to leaf abscission or decline in total leaf area, possibly a strategy for water conservation.

Leaf Growth of Different Populations of Vetiveria zizanioides

Large sample sampling was adopted in this paper for the statistical analysis of leaves of four populations of Vetiveria zizanioides （ introduced, local wild, domesticated wild populations of different years）. The results showed that four populations varied in different degrees in terms of tiller height, leaf biomass, and leaf biomass ratio. Leaf length, leaf width, and ratio of leaf width to length of different populations also varied, but had similar power-function change regularity, and showed converging leaf biomass growth pattern and leaf growth process.

Kinematic Analysis of Leaf Growth in Grasses:A Comment on Spatial and Temporal Quantitative Analysis of Cell Division and Elongation Rate in Growing Wheat Leaves under Saline Conditions

Hu and Schmidhalter （2008） conducted a study with wheat seedlings growing in saline and non-stressed （control） conditions with the aim of identifying and quantifying the cellular basis for the reduction in leaf growth. We applaud their goals as salinity is an important issue for plant ecology and food production; however, we have concerns about the methodology used and the subsequent conclusJons that are drawn.

Discovery of and Preliminary studies on a Rapid-Leafing Rice Genotype at the Vegetative Growth Stage

The leafing rates of fourteen rice varieties were measured in a sowing-time experiment, and a rapid leafing genotype at the vegetative growth stage was discovered in an indica variety Yanhui 559. The leaf number on the main culm of Yanhui 559 was always 4-5 leaves more than that of Lemont, and the leafing rate of Yanhui 559 was significantly higher than that of Lemont based on similar growth durations from sowing to heading. Furthermore, the difference of the leafing rate was significant at the vegetative growth stage, but not distinctive at the panicle initiation stage. Genetic analysis of the leafing rates in the two backcross populations of Yanhui 559 and Lemont showed that major and quantitative genes controlled the expression of rapid leafing character. Based on results of investigation for some plants with similar growth durations in the backcrossing populations, the rapid leafing genotypes exhibited earlier tillering and more tiller numbers per plant, and its yield components including the number of panicles per plant and number of grains per panicle were superior to those of the slow leafing genotypes. Further research and application feasibility of the rapid leafing genotype in breeding were discussed.

Study on visualization simulation soybean leaf based on growth equation

According to the virtual crops model research＇s need, the paper emphasized on the modeling theory and dynamic modeling methods, and took the soybean leaf as the example, introduced the establishment of leaf growth model based on growth equation, finally realized the visualization result based on OpenGL in VC＋＋ platform. The paper has great significance on establishing the whole growth model and researching the crops growth principles.

Effect of leaf and bark aqueous extract of Anogeissus latifolia on growth performance of Vigna unguiculata

The present study was carried out to assess the effect of leaf and bark aqueous extract of Anogeissus latifolia tree on Vigna unguiculata traditional crop to understand the suitability of treecrop combination in agricultural fields. Different concentrations of leaf (1%, 3% and 5%) and bark (1%, 3% and 5%) aqueous extract of A. latifolia were used to study radicle and plumule growth of Vigna unguiculata. The leaf and bark aqueous extract have shown minimum allelopathic effect on V. unguiculata and suppressed/stimulated radicle and plumule growth under different concentrations. The wide distribution of Anogeissus latifolia in a subtropical region of Garhwal Himalaya, provides good fodder fuel wood and timber to the villagers. Therefore introducing Anogeissus latifolia in agricultural field and maintaining the existed trees at boundaries of agricultural fields can be useful to the villagers requirements for the villages and wherever the possible allopathic effect exit can be minimized by lopping the branches of trees and use of naturally flecked off bark for fuel wood purposes.

Effects of sulfur dioxide on growth， gas exchange rate and leaf sulfur content of massion pine seedlings

The effects of sulfur dioxide(SO_2) on the dry weight growth gas exchange rate and leaf sulfur content of massion pine(Pinus massoniana Lamb. )were investigated. The results obtained in this study show that the dry weight growth and net photosynthetic rate of masson pine seedlings are reduced by exposure to SO_2 at ≥100 ppb. From these results,one of the main causes in the dieback of masson pine forest reported in Chongqing,China may be relatively high concentrations of atmospheric SO_2 in the relevant area.

黄芪茎叶提取物对仔猪生长性能、养分表观消化率及免疫指标的影响

文章旨在探究添加不同水平黄芪茎叶提取物对断奶仔猪生长性能、养分表观消化率及免疫机能的影响。试验将120头健康的体重(25±0.5)kg的“杜×长×大”三元杂交仔猪随机分成4组,每组3个重复,每个重复组10头,试验分别在基础日粮中添加0(1组)、1.0%(2组)、1.5%(3组)、2.0%(4组)黄芪茎叶提取物,预饲期10d,整个试验为期56d。结果表明:(1)试验3、4组平均日增重较1组分别显著提高11.6%、10.1%(P <0.05),其料重比较1组分别显著降低9.4%、7.0%(P <0.05);(2)试验3、4组粪便中的粗蛋白质、粗脂肪、粗纤维的养分表观消化率较1组分别显著提高10.9%、10.8%、10.8%、11.2%、16.5%、15.9%(P <0.05);(3)试验3、4组血清中IgA、IgG、IL-2含量较1组分别显著提高10.8%、11.7%、12.0%、13.7%、22.9%、25.1%(P <0.05),其血清中TNF-α含量较1组分别显著降低20.8%、22.1%(P <0.05)。综上所述,添加1.5%黄芪茎叶提取物可以提高“杜×长×大”二元杂交仔猪的生长性能、养分表观消化率及免疫机能。

东北槭属植物凋落叶对东北槭生长的影响及其化感作用初探

为解决东北槭小苗生长缓慢成材周期长,寻求促进其生长的途径,采用温室培养的方法,以一年生东北槭小苗为受体,通过高生长量、叶长、叶宽、冠幅、地上鲜重、地下鲜重及叶绿素含量、POD活性的测定,研究茶条槭、元宝槭凋落叶及假色槭和东北槭混合凋落叶粉碎物对东北槭小苗生长的影响。结果表明,茶条槭凋落叶对东北槭表现出了“低促高抑”的化感作用,当添加量最大120g/10kg时,小苗受到抑制。元宝槭凋落叶添加量最大时各指标促进作用显著,东北槭高生长量增加了1倍。混合凋落叶对东北槭生长无明显作用。

干旱胁迫对紫叶紫薇容器苗生长及生理的影响

为探究干旱胁迫对紫叶紫薇容器苗的生长及生理影响,以紫叶紫薇优良新品种‘丹红紫叶’2年生容器苗为研究对象,设计了5个干旱胁迫强度处理,测定不同干旱胁迫处理对容器苗生长及生理相关指标的影响。结果表明:干旱胁迫对紫叶紫薇容器苗的生长及生理的影响显著。随着干旱胁迫强度增加,紫叶紫薇容器苗叶片相对含水量、过氧化物酶活性、超氧化物歧化酶活性、可溶性蛋白含量、净光合速率、气孔导度、蒸腾速率总体上呈现降低趋势,重度干旱时这些指标分别比正常供水显著下降了21.45%、40.45%、31.92%、3.30%、81.25%、89.29%、87.17%,极重度干旱时达到最低值。可溶性糖含量、脯氨酸含量、丙二醛含量随着干旱胁迫程度增强而一直上升,重度干旱时分别比正常供水显著增加了122.92%、74.98%、288.34%,极重度干旱时达到最大值。随着干旱胁迫强度加重,过氧化氢酶活性、叶绿素相对含量、水分利用效率呈现先升高后降低的趋势,中度干旱时过氧化氢酶活性最大,叶绿素相对含量和水分利用效率则是轻度干旱最高,极重度干旱时最低。胞间CO_(2)浓度随着干旱胁迫加强而先降后升,正常供水的胞间CO_(2)浓度最高,中度干旱最低。紫叶紫薇容器苗具有抵御中度干旱的能力,当土壤相对含水量下降至30%~35%时应及时给苗木浇水灌溉。

日粮中添加不同水平杜仲叶提取物对肉牛生长性能、血清生化指标及血清免疫指标的影响

文章旨在研究日粮中添加不同水平杜仲叶提取物对肉牛生长性能、血清生化指标及血清免疫指标的影响。试验选取72头月龄相近,初重为(436.18±25.42)kg的西门塔尔公牛,随机按4组×3重复×6头分组。各组肉牛分别饲喂日粮+0%、0.1%、0.2%、0.3%的杜仲叶提取物。预饲期7d,正试期40d。结果表明:(1)与0%杜仲叶提取物组相比,0.1%杜仲叶提取物组肉牛平均日增重显著提高21.71%(P<0.05),饲料转化率显著降低10.98%(P<0.05)。(2)与0%杜仲叶提取物组相比,0.2%、0.3%杜仲叶提取物组肉牛血清中总蛋白含量显著提高(P<0.05),谷草转氨酶活性显著降低(P<0.05)。(3)与0%杜仲叶提取物组相比,0.1%、0.2%、0.3%杜仲叶提取物组肉牛血清中IgA含量显著提高(P<0.05),0.3%杜仲叶提取物组肉牛血清中IgG含量显著提高(P<0.05),0.2%、0.3%杜仲叶提取物组肉牛血清中肿瘤坏死因子-α含量显著降低(P<0.05)。结论 :日粮添加低水平(0.1%)杜仲叶提取物,肉牛生长性能最佳;日粮添加中高水平(0.2%、0.3%)杜仲叶提取物能提高肉牛血清免疫力。

剑麻专用肥对石漠化山区剑麻生长及产量的影响

石漠化山区自然条件恶劣,剑麻具备耐瘠薄、耐旱、综合利用价值高、发展前景广阔等特点,成为石漠化山区产业扶贫的较好选择。试验结果表明,剑麻新增叶片数、叶长和鲜叶产量随专用肥施入量增加而增加,每株剑麻施用专用肥量为200 g时,鲜叶产量、经济效益最高。该结论为石漠化山区剑麻高产栽培技术提供技术参考。

3种寄主植物对白刺夜蛾生长发育、繁殖和寿命的影响

白刺夜蛾Leiometopon simyrides是荒漠植物白刺的重要害虫,为明确寄主植物对白刺夜蛾生长发育的影响,以便对其进行科学监测和防控,本研究在27℃下,利用3种寄主植物(大果白刺、泡泡刺、唐古特白刺)饲养白刺夜蛾,观察记录白刺夜蛾幼虫的取食量、各阶段的发育历期、存活率、羽化率、雌雄性比和成虫寿命等生物学特性,同时测定各寄主植物叶片的营养和次生代谢物质含量。结果表明,白刺夜蛾幼虫取食大果白刺叶片的总量最少,取食唐古特白刺的量最多。取食唐古特白刺的白刺夜蛾幼虫发育历期最短,其次为取食泡泡刺,取食大果白刺时历期最长。取食泡泡刺和唐古特白刺后,白刺夜蛾幼虫的存活率和羽化率较高,取食大果白刺存活率最低,且无成虫羽化。在唐古特白刺上,白刺夜蛾雌虫占比较高,成虫寿命较长。大果白刺的叶片总酚含量和简单酚含量最高,各营养物质含量最低,不利于白刺夜蛾的生长发育;唐古特白刺和泡泡刺酚类物质含量较低,营养物质含量较高,较适宜白刺夜蛾的生长发育和繁殖。唐古特白刺为白刺夜蛾的最适宜寄主植物,其次为泡泡刺。

干旱胁迫对伊犁绢蒿幼苗生长及叶片解剖结构的影响

为探究干旱胁迫对伊犁绢蒿(Seriphidium transiliense)幼苗生长及叶片解剖结构的影响,本研究采用控水实验,对培养45 d后的幼苗进行持续干旱胁迫处理,测定幼苗的株高、根长、地上、地下生物量以及叶片解剖结构。结果表明:随着干旱胁迫程度的加剧,幼苗地上部分生长逐渐减缓,地下部分生长和根冠比则持续增加。当土壤相对含水量降至6.38%时,株高和地上生物量较对照分别降低了73.83%和73.05%(P<0.01),而根长、地下生物量和根冠比较对照分别增加了6.09%,67.92%和527.49%(P<0.01)。随着干旱胁迫程度的加剧,叶片厚度、上下表皮细胞厚度、维管束直径均呈先增后降趋势,而上下角质层厚度则表现出逐渐增加的趋势,栅栏组织呈逐渐下降趋势。综上所述,伊犁绢蒿幼苗通过调节地上部分和地下部分的生长以及叶片解剖结构的变化来应对干旱胁迫。

育苗容器对紫叶紫薇容器苗生长、开花及生理的影响

【目的】探讨育苗容器类型和规格对紫叶紫薇容器苗生长、开花及生理的影响,筛选出培育紫叶紫薇容器苗的适宜育苗容器,为高效培育紫薇容器苗提供理论依据。【方法】以紫叶紫薇优良新品种‘丹红紫叶’2年生苗木为研究材料,选用黑色塑料营养杯(C1)、白色无纺布美植袋(C2)、黑色控根容器(C3)3个类型以及16×16(D1)、21×21(D2)、25×25(D3)3种规格(直径×高,cm),组成9种容器组合处理,测定不同处理容器苗生长、开花及生理指标。【结果】(1)不同育苗容器处理对紫叶紫薇容器苗的生长、开花及生理指标均影响显著,同一容器类型苗木的生长、根系、生物量、花期、花径、花序、可溶性蛋白含量、可溶性糖含量、相对叶绿素含量、净光合速率、气孔导度、蒸腾速率等指标均随着育苗容器规格的增大而显著增加。(2)地径生长量、总根长、总根表面积、总根体积、根尖数、地上部干质量、地下部干质量、总干质量、花期均以C3D3处理最大,比最小的C1D1处理分别显著提高817.12%、108.12%、94.60%、75.66%、144.14%、135.67%、228.45%、164.65%、34.48%;苗高生长量、冠幅生长量、叶面积、花序长和宽均以C1D3处理最高,比最低的C1D1处理分别显著提高116.05%、81.39%、114.95%、70.44%和65.79%;相对叶绿素含量、水分利用效率均以C3D3处理最大,可溶性蛋白和可溶性糖含量、净光合速率、气孔导度均以C1D3处理最高;胞间CO_(2)浓度、水分利用效率在各处理之间无显著差异。(3)各处理隶属函数法综合评价得分排序为:C3D3>C1D3>C2D3>C3D2>C2D2>C1D2>C2D1>C3D1>C1D1。【结论】黑色控根容器在地径生长量、根系生长指标、生物量、花期和花径、叶绿素相对含量及净光合速率方面表现最佳;紫叶紫薇2年生苗的最适宜育苗容器是直径25 cm、高25 cm的黑色控根容器。

桂西南岩溶区植物叶性状的系统发育信号及其关联分析

【目的】探究岩溶植物叶性状在不同生活型水平上的差异以及系统发育保守性,有助于深入理解植物对异质性生境的适应机制,进而为岩溶植被的保护与恢复提供科学依据。【方法】以桂西南岩溶区20种常见阔叶木本植物为对象,采用K值法检验了叶性状的系统发育信号,并运用系统发育独立比较(PIC)和标准化主轴估计(SMA)的方法分析了叶性状间的关联适应性。【结果】1)研究区植物群落10个叶性状均未表现出较强的系统发育保守性,系统发育结构与性状结构并不完全一致。2)叶面积(LA)与叶长(LL)、叶宽(LW)以及叶组织密度(LTD)与LL、叶体积(LV)间均呈异速生长关系,而LL与LW、LA与叶干质量(LDW)间均呈等速生长关系;其中,LTD与LL的生长关系在常绿植物组发生了改变,由异速生长关系转变为等速生长关系;其他性状组合间的生长关系并未因生活型的不同而引起差异,表明常绿植物倾向于限制LL以适应环境的变化;3)LA、LL和LW以及LTD与LL、LV在常绿和落叶植物组间的斜率均沿共同主轴方向显著漂移(P<0.05),表明常绿和落叶植物对环境的适应策略发生了位移,常绿植物倾向于选择小叶、组织密度大的资源保守型生长策略,而落叶植物则倾向于选择大叶、组织密度小的资源获取型生长策略。【结论】生态位分化在很大程度上是促进亚热带阔叶林群落物种共存和生物多样性维持的重要机制。

遮阴处理对槲树幼苗生长及生理的影响

【目的】为了探明槲树(Quercus dentata)苗期生长的适宜光照强度,为其在城市森林建设应用中提供参考。【方法】以槲树幼苗为试验材料,设置全光照(CK)、75%全光照、50%全光照、25%全光照4个光照梯度,处理60 d后,测定生长指标、叶解剖结构、生理指标和光合参数。【结果】75%全光照下槲树幼苗生长状况最佳,有利于生长。随着遮阴程度增加,槲树幼苗的叶片、栅栏组织、海绵组织、主脉、上表皮和下表皮的厚度均减小,栅海比减小,而细胞疏松度增加。过氧化物酶、超氧化物歧化酶、过氧化氢酶的活性随着遮阴程度的增加先降低后升高,可溶性糖、可溶性蛋白、脯氨酸与丙二醛的含量表现出相似的变化规律。遮阴处理消除了槲树幼苗的光合午休现象,并且提高了光能利用效率,减少了暗呼吸消耗,有利于光合产物的积累。【结论】槲树幼苗具有一定的耐阴性,75%全光照是适宜槲树苗期生长的光照强度。

Varietal Differences in Plant Growth, Phosphorus Uptake and Yield Formation in Two Maize Inbred Lines Grown Under Field Conditions

Selection for phosphorus （P）-efficient genotypes and investigation of physiological mechanisms for P-use efficiency in maize has mainly been conducted at the seedling stage under controlled greenhouse conditions. Few studies have analyzed characteristics of plant growth and yield formation in response to low-P stress over the whore growth period under field conditions. In the present study, two maize inbred lines with contrasting yield performances under low-P stress in the field were used to compare plant growth, P uptake and translocation, and yield formation. Phosphorus accumulation in the P-efficient line 154 was similar to that of line 153 under high-P. Under low-P, however, P uptake in line 154 was three times greater than that in line 153. Correspondingly, P-efficient line 154 had a significantly higher yield than P-inefficient line 153 under low-P conditions （Olsen-P=1.60 mg kg-1）, but not under high-P conditions （Olsen-P=14.98 mg kg-1）. The yield difference was mainly due to differences in the number of ears per m2, that is, P-efficient line 154 formed many more ears under low-P conditions than P-inefficient line 153. Ear abortion rate was 53% in the P-inefficient line 153, while in line 154, it was only 30%. Low-P stress reduced leaf appearance, and delayed anthesis and the silking stage, but increased the anthesis-silking interval （ASI） to a similar extent in both lines. The maximum leaf area per plant at silking stage was higher in P-efficient line 154 than in P-inefficient line 153 under both P conditions. It is concluded that low-P stress causes intense intraspecific competition for limited P resources in the field condition which gives rise to plant-to- plant non-uniformity, resulting in a higher proportion of barren plants. As soon as an ear was formed in the plant, P in the plant is efficiently reutilized for kernel development.

冀北山地不同坡向白桦枝叶异速生长关系研究

当年生小枝作为植物生长的独立构件单元,研究其大小关系对于理解植物生存适应策略具有重要意义。以冀北山地不同坡向白桦枝叶为研究对象,测定小枝的茎干质量、叶片干质量、叶片面积、叶柄干质量以及小枝干质量,分析不同坡向白桦枝叶生长关系,揭示白桦枝叶生长对坡向的生态策略和适应性。结果表明:(1)除茎干质量外,其余干质量皆显示为半阳坡显著大于阴坡,叶片面积在坡向间无显著差异。(2)标准化主轴回归分析(SMA)表明,在小枝水平上,不同坡向间茎干质量与小枝干质量、总叶片干质量与小枝干质量、总叶片面积与小枝干质量均为等速关系,而总叶柄干质量与小枝干质量为异速关系;且茎干质量与小枝干质量、总叶柄干质量与小枝干质量的共同斜率1.12和1.22大于总叶片干质量与小枝干质量的共同斜率1.04。(3)在叶水平上,阴坡和半阳坡总叶片干质量与总叶柄干质量为异速关系,在半阴坡为等速关系;总叶片面积与总叶柄干质量在阴坡为等速关系,其余坡向为异速关系。(4)每个坡向叶大小与出叶强度呈负等速关系;叶大小以叶干质量表示时,阴坡异速生长常数-0.18为最小;叶大小以叶面积表示时,半阳坡异速生长常数2.01为最小。结果表明,白桦为适应坡向的变化,会优先将资源分配给茎和叶柄,且阴坡白桦小枝上会着生更多面积大而干质量小的叶片,以扩展其生长空间,获得更多的光照,利于白桦的生长。

4种忍冬属树种物候与叶生长研究

以长白忍冬Lonicera ruprechtiana、蓝叶忍冬L.korolkowii、早花忍冬L.praeflorens和金银忍冬L.maackii为研究对象,采用树木物候观测法对4种忍冬属树种的物候期进行观测记录,同时对其叶片的长度、宽度、叶面积和叶生物量进行了连续4个月的测量。结果显示:(1)4种忍冬属树种的叶期为长白忍冬(169d)>蓝叶忍冬(165d)>金银忍冬(161 d)>早花忍冬(159 d);花期为早花忍冬(18 d)>蓝叶忍冬(14 d)>金银忍冬(13 d)>长白忍冬(9 d);果实宿存为金银忍冬(198 d)>长白忍冬(50 d)>蓝叶忍冬(39 d)>早花忍冬(9 d)。结果表明:长白忍冬叶期最长,早花忍冬花期最长,金银忍冬果实宿存期最长。(2)叶片长度、宽度和叶面积变化趋势较一致。长白忍冬的叶片长度、宽度和叶面积在6月上旬达到最大,蓝叶忍冬和早花忍冬在7月上旬达到最大,金银忍冬在7月下旬达到最大。(3)4种忍冬属树种比叶面积从大到小为金银忍冬(197.88 cm2·g-1)>蓝叶忍冬(173.54 cm2·g-1)>早花忍冬(164.21 cm2·g-1)>长白忍冬(163.88 cm2·g-1),表明长白忍冬比其它3种忍冬属树种更能适应资源贫瘠和干旱的生境。在园林绿化中应充分考虑4种忍冬属树种的物候特征和生态学特性进行合理优化配置,以达到较高的观赏和应用价值。