Effect of Plant Density on Bark Yield of Cinnamon Intercropped Under Mature Rubber

Possibilities for intercropping cinnamon (Cinnamomum verum J.Pres) under rubber (Hevea brasiliensis Muell. Arg.) were investigated. In one experiment, the 9.1 m inter row space of a 15 year old rubber plantation was intercropped with cinnamon. The effect of four cinnamon densities (17,500 bushes ha⁻¹, 8,260 bushes ha⁻¹, 7,980 bushes ha⁻¹ and 3,980 bushes ha⁻¹) and four levels of fertilizer (60 g bush⁻¹, 120 g bush⁻¹, 180 g bush⁻¹ and 240 g bush⁻¹) on cinnamon bark yield and yield components were tested in a split plot experiment. Interception of light by the rubber canopy, R:FR ratio of transmitted light under the rubber canopy and the fine root length density in the inter row was uniform in all treatments throughout the whole experimental period. R:FR ratio of light under cinnamon was significantly lower under the highest cinnamon plant density of 17,500 bushes ha⁻¹. Bushes in the highest plant density treatment (D1) produced longer shoots than those in the lowest density treatment (D4), where the weight of bark cm⁻¹ was greater. As a result there were no significant effects of plant density on cinnamon bark yield at the individual bush level. This also resulted in significantly greater weight of bark per ha in the highest density treatment (D1) indicating the possibility of increasing cinnamon plant density for obtaining greater bark yield from intercropping systems under considerable shade and root competition. Increasing the level of added fertilizer even up to four times the standard did not have any advantage on bark yield or its components.     

转基因八楞海棠抗黄化鉴定研究

研究了转FRO2基因八楞海棠抗黄化性。结果显示,转FRO2基因八楞海棠植株的FRO2基因得到了过量表达;在缺铁胁迫下,转FRO2基因八楞海棠根系铁还原酶活性为对照的2.2倍;根系铁吸收能力和有效铁还原能力明显加强,叶片中有效铁含量是对照的2.1倍;转FRO2基因叶片颜色比对照绿,黄化程度减轻。在正常培养条件下,转FRO2基因八楞海棠根系的FRO2基因表达量增加,铁还原酶活性是对照的1.88倍,叶片有效铁含量是对照植株的1.7倍。转FRO2基因八楞海棠可以用于盐碱地及其缺铁土壤的生产,以解决苹果黄化问题。     

Growing and pruning dynamic recurrent fuzzy neural network optimal control on firing rate to feed water ratio for supercritical unit

By analyzing a certain once through boiler’s FR/FW control system,a new control scheme based on growing and pruning dynamic recurrent fuzzy neural network (GAP-DRFNN)is proposed. This GAP-DRFNN can synthetically study main relative state parameters about FR/FW control,so as to calculate the optimal FR/FW by using least temperature deviation value of outlet of moisture separator as its training signal. As the data of current main relative state parameters input,GAP-DRFNN through structure learning can automatically increase and pruning neurons,and adjust the parameters and the recurrent weight of neural network dynamically based on stochastic gradient descent algorithm. The experimental results show the good performance for the system in variable conditions and this scheme’s celerity and precise on FR/FW control,it has better quality than traditional PID control method.     

Physiological responses of saplings of rainforest timber species differing in successional group to light regimes and nitrogen

Saplings of 19 valuable rain forest timber species representative of three successional status groups (early secondary, late secondary and climax) were grown in a polyhouse to examine their responses to three light intensity/quality treatments and nitrogen supply. Solar radiation was modified using painted polyethylene sheet to mimic natural light environments across a rain forest vertical column as follows: 1. Transparent plastic, 80% of full sunlight, R:FR = 0.95, 2. Blue shade, 14% of full sunlight, R:FR = 0.69; 3. Green shade, 7% of full sunlight, R:FR = 0.50. Transparent plastic conditions promoted an increase in stem height and diameter (i.e., growth), leaf thickness and gas exchange per unit leaf area. Additional nitrogen availability enhanced growth and specific leaf area (i.e., leaves were thinner), particularly in the full sun environment and on early secondary and late secondary successional species, but did not influence photosynthetic rate. Successional status of the species did not affect photosynthetic rate although early secondary successional species grew faster and had fewer branches than species of the other successional groups. We recommend that for a successful mixed stand the high-light requiring species should be planted first, with increased nitrogen supply, and the shade tolerant species should be introduced later with no extra nitrogen supply required.     

不同R/FR比值对双断根西瓜嫁接苗生理及光合荧光特性的影响

为探究不同红光/远红光(R/FR)比值对双断根西瓜嫁接苗生理及光合荧光特性的影响,提高西瓜嫁接苗种苗品质,对双断根西瓜嫁接苗进行不同光质处理,共设置4种光质组合：黑暗(D)、白光(W)、高比值R/FR(R/FR=3,H)和低比值R/FR(R/FR=0.3,L),以黑暗为对照,分析西瓜嫁接苗幼苗形态、渗透调节物质、抗氧化酶系统和光合荧光特性。结果表明：与对照相比,L处理显著提高了西瓜嫁接苗的成活率和生长指标,显著提高接穗叶片中的抗氧化酶活性(SOD和POD)、可溶性糖和可溶性蛋白质量分数,同时显著降低了O^2-、H₂O₂和MDA的积累。L处理对西瓜嫁接苗光合系统也有一定影响：处理8 d时,嫁接苗光合特性指标、Fv/Fm、Fv’/Fm’和ФPSⅡ显著升高,NPQ显著下降;而长时间处理(20 d)会导致叶绿素质量分数以及光合特性指标降低,Fv/Fm、Fv’/Fm’、ФPSⅡ和qP下降,NPQ显著升高。综上,低比值R/FR处理能够通过增强西瓜嫁接苗抗氧化能力并影响光合作用的过程,最终促进双断根西瓜嫁接苗的成活及生长。     

荫蔽信号对大豆幼苗生长和光合特性的影响

红光/远红光比值(R/FR)下降是自然界荫蔽发生的重要信号。为探究大豆幼苗对荫蔽信号的应答机制,本文采用室内盆栽试验,以‘南豆12’和‘南032-4’两个大豆品种幼苗为材料,通过正常光照和低R/FR两种光照处理后,对其形态、光合特性以及叶绿素荧光参数进行研究。结果表明:与正常光照相比,低R/FR下,两个大豆材料幼苗均表现出典型的避荫性反应,即株高、叶面积、叶柄长、节间长增加,茎秆变细,其中,‘南豆12’的株高、叶柄长、节间长分别显著增加7.86%、81.48%、26.55%,‘南032-4’分别增加3.95%、76.67%、20.00%;叶片的光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)提高,胞间二氧化碳浓度(Ci)和初始荧光强度(Fo)、最大荧光(Fm)、最大光化学效率(Fv/Fm)、PSⅡ实际光化学效率(ΦPSⅡ)、光化学淬灭系数(q P)等降低,非光化学淬灭系数(q N)升高,总干物质积累量增加,其中,‘南豆12’和‘南032-4’的Pn分别增加37.21%和39.04%、总干物质积累量分别增加12.35%和17.36%、Ci分别降低9.29%和11.72%。然而,不同大豆材料对低R/FR的敏感程度不同。在低R/FR光环境下,‘南豆12’较‘南032-4’表现出较低的株高、节间长、叶柄长,较大的叶面积和茎粗,较高的光能传递转换效率、Pn、Gs以及干物质积累量,体现了对荫蔽较强的适应性。本研究进一步证实了大豆具有感受荫蔽信号(低R/FR)的能力,但其敏感程度因品种不同而不同,在间套作过程中,为提高大豆耐荫性,降低大豆因避荫反应导致的倒伏率,保障大豆产量,应该选择对荫蔽信号不敏感的品种。     

Involvement of phytochrome B in DIF mediated growth in cucumber

This study aimed to compare the interaction between light quality and alternating day (DT) and night temperature (NT) under two different daily light integrals (DLI) on morphology of a wild type (wt) and a phytochrome B deficient mutant (lh) of cucumber (Cucumis sativus L.). Different light qualities were established by light quality selective plastic films. Plants were grown for 18 days (lh) or 19 days (wt) under DT/NT regimes of 25/19 °C (positive DIF), 22/22 °C and 19/25 °C (negative DIF) (12-h thermoperiod) in combination with plastic films establishing a low (0.75, LRFR) and high red (R)/far-red (FR) ratio (1.62, HRFR) and a control (R/FR of 1.11). Stem, hypocotyl and internode elongation in the wt were more affected by DIF under LRFR than HRFR. In general, length was reduced 45–50% under HRFR compared to the control, while the reduction by negative DIF was 38% on average. Hypocotyl length of the lh mutant was neither affected by temperature regime nor light quality, while negative DIF reduced stem length with 15–20% compared to positive DIF due to a delayed internode elongation. The general response pattern in both genotypes was not affected by an additional reduction in DLI of 50%. In conclusion, the strongest effect of DIF was found under a LRFR which is the opposite of findings in earlier studies with day extentions with different light qualities. In general, HRFR reduced stem elongation of cucumber more than negative DIF. The results indicate a crosstalk between light phytochrome responses and thermoperidism.