Analysis of Leaflet Shape and Area for Improvement of Leaf Area Estimation Method for Sago Palm (Metroxylon sagu Rottb.)

Abstract

Leaf area of sago palm (Metroxylon sagu Rottb.) can not be estimated accurately from the whole leaf shape, and individual leaflet area must be measured for accurate estimation of leaf area. In this study we examined leaflet characteristics in detail and developed a method of estimating individual leaflet area. Shapes of all leaflets were similar regardless of their sizes. The leaflet width was maximal at the distal position around 30 ～40] from the leaflet base. Products of leaflet lengths and maximum widths (as the X-axis) showed almost a linear relationship with the leaflet areas measured with a leaf area meter (as the Y-axis). Moreover, the Y-intercept of the primary regression equation was very small compared to leaflet area values, and we can regard it as 0. We compared the measured leaflet area with the area of the ellipse with the leaflet length as the major axis and the maximum width as the minor axis. The difference between them was within±15] except for some leaflets at the base or tip of the leaf. These results suggested that the method of estimating leaflet area from the ellipse area calculated from the leaflet length and the maximum leaflet width as major and minor axes, respectively was simple and accurate. The estimation equation for the leaflet area is S(e)=0.785 L_leaflet×W_leaflet, where S(e) is the estimated leaflet area, L_leaflet is the leaflet length, and W_leaflet is the maximum leaflet width.     

橄榄种质资源叶片表型性状多样性分析

对农业部福州橄榄种质资源圃中80份橄榄种质资源叶片12个表型性状进行了调查分析.结果表明:这一群体橄榄种质资源的嫩叶颜色、成熟叶颜色、叶面光泽度、叶片形状、叶尖形状、叶基形状、小叶数、复叶主轴长度、小叶叶柄长度、小叶长度、小叶宽度、叶形指数等表型性状均存在丰富的多样性;不同来源地橄榄种质资源叶片表型性状差异明显.主成分分析结果表明,叶片形状、叶形指数、嫩叶颜色、成熟叶颜色、小叶数是叶片表型性状多样性构成的主导因子.     

Position and Development of Differentiated Lateral Buds in Sago Palm (Metroxylon sagu Rottb.)

Abstract:

During sago palm cultivation, many suckers appear from the mother stem as it grows. Some suckers are thinned out, but the rest are left to grow to be harvested several years later after harvesting of the mother stem (trunk). Proper management of the suckers from the mother stem is important to obtain successive sago trunks from a single transplantation. Nevertheless, little scientific knowledge exists about the sucker growth, even the development of its primordium. Our objective is to clarify the differentiation position and the development of the sago palm lateral bud, which is the sucker bud. Results show that in sago palm, the sucker bud differentiates inside of the connate part of the leaf petiole, which is opposite to the axil side. Swelling of tissue is first visible inside of the third leaf from the growth point (rbL 3). Sucker bud initiation is visible at almost all leaf positions lower than rbL 5. Furthermore, at each leaf position, one or two (rarely three) buds are observed. Differentiated buds usually elongate exponentially. Some develop more than two times on average. These sucker buds differentiate inside of the connate part of the thin leaf petiole, which split toward the base gradually as new leaves emerge. The differentiation position of the sucker buds and the thin leaf petiole are expected to be related closely to the further growth of the large sucker buds.     

Effect of Low pH on the Growth,Physiological Characteristics and Nutrient Absorption of Sago Palm in a Hydroponic System

Abstract

The dry matter production, photosynthetic characteristics and nutrient concentrations in the plant tissues of sago palmseedlings cultured for 4.5 months in a hydroponic system at pH 5.7, 4.5, and 3.6 were examined. Plant growth in weekly increment of length, leaf emergence, leaf senescence, and total leaflet area was similar at all pHs. There was no significanteffect of pH on the dry matter weight, although it tended to be lighter at pH 3.6 than at pH 5.7. Similarly, the photosynthetic rate and its related parameter were not significantly affected by the pH. However, the photosynthetic rate at pH 3.6tended to be lower than that at pH 5.7, which was attributed to a decrease in the stomatal conductance. The effect of the low pH on the nutrient concentration in plant tissues was not distinct. We concluded that sago palm seedlings could maintain leaf morphogenesis and nutrient uptake in growth media at a pH ranging from 5.7 to 3.6 for 4.5 months, which led to a high growth rate and maintenance of dry matter production even at pH 3.6.     

Estimating leaf area of warm‐season perennial legumes

Refining mathematical models may decrease labour and generate accurate estimates of leaf area in warm‐season perennial legumes. The aim of this study was to assess the use of mathematical models to determine the leaf area of four tropical forage legumes. Perennial legumes (Arachis pintoi, Stylosanthes spp., Calopogonium mucunoides and Neonotonia wightii) were collected, and an elliptical model and a corrected elliptical model were used to estimate leaf area. For comparison, linear models were also generated based on the leaflet area. The elliptical model was suitable for the initial forage peanut leaflets, while the corrected elliptical model proved suitable for estimating the area of the initial leaflets of all species as well as the terminal leaflets of forage peanut and stylo. The elliptical model could be used to estimate the area of both the initial and terminal leaflets only in stylo. Models were generated to estimate leaf area of all legumes requiring only the measurement of length and width from a single initial leaflet. In all of the studied legumes, the leaflet pairs were symmetrical, meaning the corrected elliptical model allows for the estimation of the leaflet area of each plant.     

Leaf Positions of Potato Suitable for Determination of Nitrogen Content with a SPAD Meter

Abstract

Hand-held SPAD meter can be used to evaluate the leaf nitrogen status of potato. For practical use, it is necessary to select a proper compound leaf, a proper leaflet within compound leaf and position of leaflet suitable for measurement. Therefore, field experiments were conducted in northern China in 2009 and 2010. The SPAD values, plant growth, N uptake of potato plants at tuber initiation and tuber bulking stages under different N supply levels, and final tuber yields were examined. The criteria for determining the most suitable leaf, leaflet and position within a leaflet are that the SPAD values show less variation at a given N supply level, and show a more sensitive response to different nitrogen levels. Our results showed that the coefficients of variance of SPAD values ranged from 8.7 to 25.9% with a leaf N concentration range of 2.1 to 3.8 gN 100 g-¹ at tuber initiation stage, and 7.2 to 21.6% with leaf N concentration range of 0.96 to 1.26gN 100 g-¹ at the tuber bulking stage. The SPAD values of the 4th compound leaf from apex were more stable and more sensitive to the nitrogen level than those of other leaves, suggesting that the 4th compound leaf is suitable for estimating the leaf N status using a SPAD meter. Within a compound leaf, the SPAD value of the top leaflet was more sensitivethan the other leaflets to nitrogen supply, whereas it was less stable, making it difficult to chose the leaflet for measurement. However, the top leaflet emerges and expands much earlier than the side leaflets, and should be better for SPAD value measurement. The SPAD measurements at the top point of the top leaflet of the 4th leaf demonstrated both less variation and higher sensitivity to nitrogen supply. Therefore, we conclude that the top point of the top leaflet of the 4th compound leaf is the best position for potato N status diagnosis using a SPAD meter.     

油棕不同叶序五种营养元素含量的测定及变化规律研究

本文首次根据油棕叶片在树冠轮生的规律,对不同成熟度的叶片进行排序,进而对不同叶序的N、P、K、Ca、Na五种营养元素含量进行了测定,并对其变化规律作了分析与研究,结果表明：(1)不同油棕树体五种营养元素含量有所差异;（2）从整体看,第8至26叶,Ca含量上升,Na含量略微上升,而K含量则下降, N和P则没有一定的规律性;（3）成龄树K含量变化范围为0.41%～1.08%;Ca含量变化范围为0.47%～1.03%;Na含量变化范围为0.011%～0.052%;N含量变化范围为1.83%～2.30%;P含量变化范围为0.12%～0.19%。（4）本试验中第20～22叶营养元素含量变化幅度小,比较稳定,可为我国油棕营养诊断取样提供较为科学的参考,与马来西亚第17叶采样标准有所差异。     

N素基蘖与穗肥不同比例对水稻群体指标的影响

通过东风、西安两地大区试验,探讨了N素基蘖与穗肥不同比例对水稻群体各指标的影响。结果表明,N素基蘖与穗肥比为25∶3∶的GN处理,在N-n叶龄期够苗后,高峰苗得到较好控制,获得高成穗率;抽穗到成熟期干物质积累量最高,分别为708.9、743.4 kg/667 m2,两处理的产量也最高,分别为759.7、805.9 kg/667 m2;基蘖肥所占比例的增加有利于提高分蘖率,对叶龄影响不大,但过重施用基蘖肥,无效分蘖多,高效叶面积率和有效叶面积率降低,而适量增加穗肥,有利于提高高效叶面积率和有效叶面积率。     

Chemical characterization of various parts of nipa palm (Nypa fruticans)

The current study was initiated to characterize various parts of nipa palm (Nypa fruticans) to establish whole utilization of this biomass as potential raw material for fuels and chemicals. Nipa consisting of frond, shell, husk and leaf was chemically characterized for cellulose, hemicellulose, lignin, starch, protein, extractives and inorganic constituents for its each part. The total chemical composition showed that the cellulose and hemicellulose contents were in the range of 28.9-45.6 wt% and 21.8-26.4 wt%, respectively. The hemicellulose was rich with glucuronoxylan. The lignin content was 19.4-33.8 wt% with the highest lignin content found in leaf. The alkaline nitrobenzene oxidation products showed that nipa palm lignin mainly consists of guaiacyl and syringyl propane units with a small amount of p-hydroxyphenylpropane unit. Besides the main chemical components, starch, protein and extractives were also present in significant amounts from 2 to 8 wt%. Additionally, the ash content was high from 5.1 to 11.7 wt%, consisting of the major inorganic elements being Na, K and Cl with minor inorganic elements of Mg, Ca, Si, P, S and Al. Overall, each part of the nipa palm has its individual superior characteristics and could be exploited as lignocellulosic resources for fuels and chemicals.     

Estimates of the leaf area of forage peanut for use in morphogenetic assessment

Understanding the morpho-physiological responses of forage plants is critical for successfully managing pastures; however, there is no specific method for morphogenetically assessing Arachis pintoi. The present study aimed to develop and validate mathematical models to estimate leaf area in A. pintoi to enable assessments of leaf elongation and senescence. Two experiments were performed. The first experiment used 500 A. pintoi leaves to model leaf area. Three models were used: correlation, mechanistic and empirical. A total of 336 leaflets were collected to validate the models. For the second experiment, 786 leaflet pairs were collected to test the leaf symmetry. Leaf length (L), width (W) and area (A) were measured for each leaflet in both of the experiments. The model identity test was used. The leaflet area can be estimated using the following formula:  = W ×L × 0·25 × π. Experiment 2 showed that the initial leaflet pairs were equal, as were the terminal leaflet pairs. In conclusion, the mechanistic model should be used to estimate the leaf area for A. pintoi, and only half of each leaf can be measured.     

Control of foliar diseases by the axillary application of systemic fungicides in Brazilian coconut palms

Endemic fungal foliar diseases, such as leaf blight – LB [Lasiodiplodia theobromae (Pat.) Griffon and Maubl] and leaf verrucosis, or “lixa-pequena” – LP [Camarotela torrendiela Batista (Bezerra) and Vitoria], reduce the productivity of the coconut palm in Brazil. Damage arises from extensive necrosis of the leaflets, resulting in early abscission of basal leaves and fruit. In Brazil, fungicide terrestrial sprayings has not been a commonly employed practice for the control of coconut foliar diseases because it is not cost-effective, once requiring high-volume of fungicide spraying. Coverage gaps and extensive drift of chemicals can occur due to technological limitations of terrestrial spraying of the tallest mature trees and is further complicated by the peculiar architecture of the palms. The aim of this study was to evaluate the efficacy of systemic fungicides applied directly to the leaf axil of the coconut palm (variety Brazilian Green Dwarf of Jiqui) for the control of foliar diseases. During 2007–2010 and 2009–2012, two field plot experiments were conducted at distinct locations (farms) in the North Fluminense region. Two to 4-monthly applications of the fungicides to the leaf axil of cyproconazole (alone), cyproconazole plus azoxystrobin, cyproconazole plus trifloxystrobin, and flutriafol (alone) were efficacious in controlling coconut palm leaf diseases, resulting in a significant reduction of the LB severity and the number of necrotic LP lesions. When compared with the control treatment, significant increases in the total number of leaves per plant were observed for the most efficacious treatments after one year (2–4 leaves more) and after the second year (3–6 leaves more) after initiating the axillary applications of fungicides in both experiments. This trend continued even after the third year, when there was an average of 8 leaves more for the most efficacious treatment (27 leaves per plant) compared to control (19 leaves per plant) at the end of second experiment. The control of foliar diseases based on the results could ensure a significant increase in regional coconut production.     

多遥感光谱指标结合进行大田冬小麦叶片叶绿素含量估测研究

为解决大田冬小麦叶片叶绿素含量估测模型精度低、通用性弱的问题,在获取冬小麦拔节期和抽穗期冠层红光波段反射率(BR_red)和近红外波段反射率(BR_nir)的基础上,计算归一化差值植被指数(NDVI)、差值植被指数(DVI)、比值植被指数(RVI)、土壤调节植被指数(SAVI)、改进型比值植被指数(MSR)、重归一化植被指数(RDVI)、II型增强植被指数(EVI2)和非线性植被指数(NLI)等8个植被指数。经统计分析,选择与叶片叶绿素含量(SPAD值)相关性较好的5个遥感光谱指标(NDVI、MSR、NLI、BR_red和RVI)作为输入变量,建立了冬小麦叶片叶绿素含量的BP神经网络估测模型(WWLCC_BP),并对估测模型进行精度验证。结果表明,WWLCC_BP估测模型在拔节期估测的决定系数(r²)为0.84,均方根误差(RMSE)为5.39,平均相对误差(ARE)为9.87%。抽穗期的估测效果与拔节期较为一致。将WWLCC_BP和高分六号影像...     

【Short Report】Identification of Chromosome Regions Affecting Leaf Area with Rice Chromosome Segment Substitution Lines

Abstract

The aim of this study was to obtain the information for improvement in source ability via expansion of a flag leaf area in rice (Oryza sativa L.). We identified chromosome regions affecting a trait (CRATs) for leaf area and confirmed their effects with two sets of chromosome segment substitution lines developed from indica landraces Kasalath or Nona Bokra as a donor under japonica cultivar Koshihikari genetic background. We detected 4 and 8 CRATs that increased leaf area by Kasalath and Nona Bokra alleles, respectively. With the Nona Bokra allele, CRAT on chromosome 7 (LA7) increased leaf area by 54% comparing to Koshihikari. LA7 maintained the contents of Rubisco and photosynthetic rate and as a result its “estimated” source ability of a flag leaf was increased by 23%. The effect of LA7 was stable under different environmental conditions, and might be useful for breeding rice with higher source ability and yield.     

氮肥配置对空育131物质生产与产量的影响

以不同氮肥配置栽培的水稻空育131为材料,测定其干物质生产和产量等的变化。结果表明,供试品种在不同氮肥配置下的群体生长发育情况不同,氮肥在基蘖肥、调节肥、穗肥、粒肥中的比例以75:20:5对空育131的群体茎数动态、叶片氮含量、叶面积及地上干物重有促进作用而明显提高产量。     

Antioxidant Capacity and Damages Caused by Salinity Stress in Apical and Basal Regions of Rice Leaf

Abstract

We investigated the mechanisms of increased sensitivity to Na⁺ in the apical and basal regions of the rice leaf under salinity. Three-week-old plants were treated with 200 mM NaCl in hydroponic culture for 3 d. Segments 6 cm in length were obtained from the apical and basal regions of the fully expanded uppermost leaves (6th leaf blades) as old and young tissues, respectively. In the plants exposed to 200 mM NaCl, Nitro blue tetrazolium (NBT) reducing activity, and H₂O₂ and Malondialdehyde (MDA) contents significantly increased, accompanied by the swelling of thylakoids and destruction of thylakoid membranes in the apical regions. However, no indication of oxidative damages was observed in the basal region, even though the Na⁺ content in the basal region was comparable to that in the apical region. In the apical region, the capacity to scavenge H₂O₂ was lower than that in the basal region due to decrease in the constitutive levels of ascorbate peroxidase and guaiacol peroxidase. In addition, the activities of antioxidant enzymes except superoxide dismutase and guaiacol peroxidase decreased drastically after 48 hr of exposure to NaCl. By contrast, the activities of catalase and glutathione reductase in the basal region increased compared with those in the control, and other antioxidant enzymes did not decrease under salinity during the experimental period. These results suggest that the capacity to scavenge reactive oxygen species decreased with age, and thus the apical region of the leaf blade suffered severer damage by Na⁺ than the basal region.     

大豆品种叶部性状与光合速率关系的研究

本试验以20个大豆[Glycine max (L) Merr]品种为试材对叶部形态、生理性状及解剖特征进行了测定,加以相关和通径分析,并首次对10个叶部光合性状进行主成份分析。研究表明:(1)叶形指数与光合速率呈负相关,表现为很小的负效应。(2)单位叶面积的叶绿素、全N含量均与光合速率呈正相关,表现为正效应。(3)比叶重与光合速率呈正相关,表现为极小的正效应,且通过叶片厚度的间接正效应远大于其直接效应。(4)叶片厚度与光合速率呈极显著正相关,表现为正效应。(5)栅栏细胞数目与光合速率呈极显著正相关,表现为较高的正效应。(6)栅栏、海绵组织厚度与光合速率分别呈极显著和显著正相关,但均表现为负效应。分析表明:通径分析与主成份分析相结合的方法是进行光合速率综合的间接选择的有效方法。     

不同叶龄期水稻秧苗对水分亏缺反应的探讨

水分亏缺对秧苗生长影响的研究甚多,但有关水稻秧苗本身对水分亏缺反应的研究报道尚不多见。本研究着重探讨了水稻不同叶龄期秧苗对水分亏缺的敏感程度、忍耐力及其生物学原因,为合理掌握旱秧育秧期水分管理提供理论依据。1 材料与方法选用杂交中籼汕优63和早熟晚粳武育粳2号为材料,在塑料顶蓬内的盆钵中进行。供试土壤为砂壤土,最大持水量为29.6%。1) 分期播种,培育不同叶龄的旱秧。从6月28日至7月23日,每隔3～6d播一期,共计6期。7月23日播最后一期后,各期秧苗全部停止水分补给。在此之前,适当给水,保持表土潮湿,以保证秧苗正常生长。2) 各播期分别设置浅土层和深土层两个处理:“浅土层”处理的土层厚度为5cm,5cm以下用塑料膜隔开,防止深层土壤水分上升及秧根下扎,用以探讨秧苗对水分亏缺的生物学反应。“深土层”处理的土层厚度为25cm,模仿旱地育秧的生长环境,用以探讨秧苗对水分亏缺的农学反应。     

向日葵叶片动态及功能叶的研究

本文研究了向日葵叶生长动态及功能叶。最初8叶对生,其余轮生。现蕾前叶从茎底部向顶端依次已全部长出,现蕾后到开花阶段则全部展开、扩大,开花期最大叶面积可达1.4m以上。植株呈两头小中间大株型。开花前底部叶片开始黄落,灌浆阶段仅余69％的叶片。生长过程上部邻近的展开叶给新生叶及花盘提供光合产物。主要功能叶层,在花序及开花阶段为植株中部偏上的第19—30叶、灌浆阶段为靠近花盘的第31—39叶,这些叶片的光合强度较大,平均3g/m~2/小时,距花盘越远的叶片功能越小。     

Potato Stem Density Effects on Canopy Development and Production

Controlled environment studies with potato frequently assume responses from single-stem potato plants can be extrapolated to the field where multiple-stemmed plants are common. Controlled environment studies were conducted to characterize differences in canopy growth, development, and dry matter production between single- and multiple-stemmed potted potatoes. Leaf area distribution was influenced by stem density, with main stem and apical lateral branch leaf area being 150% to 200% larger in triple-stemmed (3S) versus single-stemmed (1S) pots (P < 0.01), while basal lateral branch leaf area was 50% less (P < 0.01). Basal lateral branches were more developed in 1S pots with longer branch lengths, more leaf area, and higher orders of branching. In a second experiment, more leaves were initiated in higher-density pots; however, individual leaf areas were approximately 50% smaller than those in 1S pots. Total leaf area and total, vegetative, and tuber dry matter production were unaffected by stem density in either experiment on a per pot basis. Development and growth of lower basal lateral branches in the 1S potato canopy offset any initial advantage in leaf numbers in the multiple-stemmed plants. These results appeared to validate the assumption that, given a late maturing cultivar and adequate nutrition, responses from single-stemmed plants can be extended to multiple-stemmed plants when expressed on a production area basis. These findings have practical considerations for potato researchers who conduct growth chamber experiments and potato modelers.     

Grids in groud cover measurements

Summary Two methods for measuring the proportion of crop ground cover were compared. Both employed a rectangular grid of cords fitted in a frame at regular distances. One was based on the proportion of rectangles in which green area occupied more than half, and the other was based on the proportion of intersects coinciding with green area. The second method was accurate under all circumstances. Whereas the first method was found to give biased records when the smallest details in the canopy were small compared to the grid cell size. A theoretical estimate of the standard error of the intersect method was derived for homogeneous canopies and confirmed by experimental data.