Leaf SPAD Value Research Articles

The Correlation of Leaf SPAD Value at Different Part of Blade with Nitrogen Nutrient Status in Sugarbeet

The Correlation of Leaf SPAD Value at Different Part of Blade with Nitrogen Nutrient Status in Sugarbeet

Ridge tillage improves plant growth and grain yield of waterlogged summer maize

Regulation of ridge tillage on yield and growth of waterlogged summer maize hybrids Denghai 605 (DH605) and Zhengdan 958 (ZD958) were investigated in field conditions. Results showed that waterlogging significantly decreased leaf area index (LAI), SPAD value, and biomass, resulting in the reduction of photosynthetic rate, thereby decreased grain yield of summer maize. Grain yields of DH605 and ZD958 were decreased by 38% and 42% respectively, compared to no waterlogging treatment. However, ridge tillage was conducive to alleviate the adverse effects of waterlogging on photosynthetic performance and photosynthetic effective radiation by increasing LAI and SPAD value, and improving canopy structure. At tasseling stage (VT), the light transmittance of ear layer in ridge tillage treatment for DH605 and ZD958 was decreased by 12% and 19%, respectively, compared to that of waterlogging treatment. Visibly, ridge tillage effectively alleviated leaf senescence and the decrease of LAI and chlorophyll content induced by waterlogging, and improved canopy structure, photosynthetic effective radiation, and photosynthesis of waterlogged summer maize, and thus increasing grain yield by 39% and 50% for DH605 and ZD958, respectively, compared to waterlogging treatments.

Effects of water-controlled irrigation on maize yield and photosynthetic characteristics of ear leaf in Xinjiang Province, China.

In order to explore the suitable water management patterns for high yield of spring maize under drip irrigation in oasis regions of North Xinjiang, two maize cultivars (Zhengdan 958 and Kenyu 02) were used to study the effect of water-controlled irrigation on the leaf SPAD value at V12-R5 stage, and chlorophyll content, photosyntheticcharacteristics and chlorophyll fluorescence parameters of ear leaf at filling stage in the field. Results showed that the leaf SPAD values peaked under moderate soil moisture treatments during V12-R3 stage. The field capacity of soil moisture above 65% was suitable for the development of corn at R5 stage. The chlorophyll a, b and total chlorophyll contents, carotene, chlorophyll a/b were significantly decreased when soil moisture was less than 75%, however the above parameters had no significant difference when soil moisture was more than 85%. The net photosynthetic rate (Pn), transpiration rate (Tr) and stomata conductance (gs) of ear leaf were significantly decreased in filling stages when soil moisture was less than 75%, but the intercellular CO2 concentration (Ci) was significantly increased. The reduction of gs was not observed when the soil moisture was more than 85% of field capacities. Meanwhile, the variable fluorescence to maximal fluorescence (Fv/Fm), potential activities of PSII (Fv/Fo), PS2 actual photochemical efficiency (ΦPS2), photochemical quenching (qP) and electron transport rate (rETR) decreased significantly under both higher and lower soil moisture treatments. However, the Fo/Fm and non-photochemical quenching (NPQ) significantly increased at the same time. The path analysis showed that the decrease of Pn resulted from the decrease of Fv/Fo and rETR, which finally resulted in decreased production of spring maize. Therefore, the optimal field moistures for these two spring maize cultivars were >60%, >70%, >75%, >80% and >65% for the growing stages V6, V12, R1, R3 and R5, respectively, to obtain a high yield in the oasis region.

Nitrogen redistribution and its relationship with the expression of GmATG8c during seed filling in soybean

It is well known that some nitrogen in the vegetative organs is redistributed to the seeds during seed filling in soybean (Glycine max [L.] Merrill). This redistribution is considered to affect the seed yield of soybean. However, it is still not clear when the nitrogen moves from the vegetative part to the seeds, and the relationship between nitrogen redistribution and leaf senescence has not been clarified. The soybean variety Fukuyutaka was grown in the experimental field of Saga University, Japan from 22 July to 31 October, 2014. After the first flower stage (R1), the plant samples were collected weekly and were separated into leaf, petiole, stem, podshell and seed. The nitrogen concentrations in each plant part were determined. Fresh leaf samples were provided for the determination of soluble protein and autophagy gene GmATG8c expression. The nitrogen that accumulated in the vegetative parts reached its highest level at 60days after sowing (DAS), then began to decrease at 73DAS (R6). This decrease is considered to be the consequence of nitrogen redistribution from the vegetative parts to the seeds. The movement of nitrogen from the vegetative parts to the seeds was estimated to occur at around 73DAS (R6). At this stage, leaf SPAD values, leaf nitrogen, and soluble protein concentrations began to decrease simultaneously, suggesting the onset of leaf senescence. Furthermore, the expression of the autophagy gene GmATG8c in the leaves increased dramatically from 73 to 85DAS, which is the duration of nitrogen redistribution. The results suggest that the nitrogen redistribution from the vegetative parts to the seeds could be one of the initiating factors of leaf senescence, and the autophagy gene GmATG8c was associated with this process.

VARIABILITY OF RICE YIELD WITH RESPECT TO CROP HEALTH

Chlorophyll content of leaf can be used as an indicator of the crop health. The SPAD chlorophyll meter has been acceptably used for rapid analysis of chlorophyll content and nitrogen status of crops while it has not been established how strongly the SPAD values are correlated with rice yield within a plot. This study was to explore the relationship between rice yields and the leaf SPAD value of the associated rice plots. Twenty sampling points of rice leaves plant were taken at three difference growing stages based on grid point sampling of 30m x 18m for two crop seasons. Two methods, namely instantaneous yield from on-board yield monitoring system mounted on a combine harvester and estimated crop yield from cutting test (CCT) yield were used to measure the variability of harvested rice yield within the rice plot. The SPAD values were found positively correlated with grain yield at different growth stages. The highest significant correlation was at crop age 70 days after planting with Pearson’s correlations (r) ranging 0.7280 to 0.8336 (P<0.001). Consequently, information with regards to SPAD value variability could triggers farmers in taking immediate in situ action for improving the crop yield while information with regards to crop yield variability could assist farmers in planning the proper farming practice for the subsequent cropping seasons. Generally, this available technology would assist farmers in improving their crop yield and their economic status.

Phytotoxicity of Fluoride in Guar (Cyamopsis tetragonoloba) Cultivars and its Effect on Morpho-Physiological and Biochemical Traits

This study reports the influence of 0 (1.42), 25, 50, 100, 200 and 400ppm (artificial contaminated water) fluoride on guar (Cyamopsis tetragonoloba L. cultivar local and sadabahar). Seedlings showed decrease in the following morphophysiological and biochemical characteristics: growth, leaf area expansion, SPAD value, chlorophyll fluorescence, yield and antioxidant enzymes, i.e. catalase, peroxidase and superoxide dismutase. At 400ppm F-contaminated irrigation water the average leaf area expansion (∼58 and 45%), shoot-root length (∼45, 46% (local) and ∼23, 54% (sadabahar), SPAD value (∼11, 25, 18% (local) and ∼12, 20, 15% (sadabahar), Fv/Fm (∼8, 11, 16% (local) and ∼6, 9, 12% (sadabahar), catalase (∼21 and 16%), peroxidise (∼42 and 38%) and SOD (∼40 and 39%) in local and sadabahar cultivar, respectively. With increasing F concentrations, growth, physiological and enzyme activity were successively reduced with days and duration of treatment frequency.

Estimating leaf SPAD values of freeze-damaged winter wheat using continuous wavelet analysis

Freeze injury, one of the most destructive agricultural disasters caused by climate, has a significant impact on the growth and production of winter wheat. Chlorophyll content is an important indicator of a plant's growth status. In this study, we analyzed the hyperspectral reflectance of normal and freeze-stressed leaves of winter wheat using a spectro-radiometer in a laboratory. The response of the chlorophyll spectra of plants under freeze stress was analyzed to predict the severity of freeze injury. A continuous wavelet transform (CWT) was conducted in conjunction with a correlation analysis, which generated a correlation scalogram that summarized the correlation between the chlorophyll content (SPAD value) and wavelet power at different wavelengths and decomposition scales. A linear regression model was established to relate the SPAD values and wavelet power coefficients. The results indicated that the most sensitive wavelet feature (region E: 553 nm, scale 5, R2 = 0.8332) was located near the strong pigment absorption bands, and the model based on this feature could estimate the SPAD value with a high coefficient of determination (R2 = 0.7444, RMSE = 7.359). The data revealed that the chlorophyll content of leaves under different low temperatures treatments could be accurately estimated using CWT. Also, this emerging spectral analytical approach can be applied to other complex datasets, including a broad range of species, and may be adapted to estimate basic leaf biochemical elements, such as nitrogen, cellulose, and lignin.

Effect of HCO $ _3^ - $ on rice growth and iron uptake under flood irrigation and drip irrigation with plastic film mulch

AbstractThere has been a partial shift away from conventional flood irrigation (FI) practices for rice (Oryza stativaL.) production in water‐scarce northern China. Drip irrigation with plastic film mulch (DI‐PFM) can maintain high rice yields with significant water savings. However, rice seedlings often develop chlorosis when grown with DI‐PFM on calcareous soil. Bicarbonate is a concern with regard to chlorosis in calcareous soil. The objective of this simulation experiment was to determine the effect of irrigation method and irrigation water HCO$ _3^ - $concentration on (1) soil pH and DTPA‐Fe concentration, (2) chlorophyll, total Fe, and active Fe concentrations of rice leaves, and (3) rice root and shoot biomass. The experiment consisted of four treatments: FI with water containing either 2 or 10 mM HCO$ _3^ - $(referred to as FI‐2 and FI‐10, respectively) and DI‐PFM with water containing 2 or 10 mM HCO$ _3^ - $(referred to as DI‐2 and DI‐10, respectively). The results show that the HCO$ _3^ - $concentrations of the soil solution were greater under FI than under DI‐PFM, because more irrigation water was applied in the FI system. Soil pH increased as the HCO$ _3^ - $concentration of the irrigation water increased. The increase in soil pH was greater in DI‐PFM than in FI. Soil DTPA‐Fe concentration, leaf SPAD values, leaf total Fe concentration, leaf active Fe concentration, shoot biomass, and root biomass decreased as the HCO$ _3^ - $concentration of the irrigation water increased. The decreases were less under DI‐PFM than under FI. Overall, the results indicate that rice plants are more sensitive to the HCO$ _3^ - $concentration of irrigation water under FI than under DI‐PFM.

The effect of nitrogen level on rice growth, carbon-nitrogen metabolism and gene expression

AbstractAs one of the essential macroelements, nitrogen (N) plays an important role in plant growth and development. In order to know the effect of different N levels on the rice plant growth and carbon-nitrogen metabolism, we analyzed the rice growth phenotype, leaf SPAD value, photosynthesis, carbon-nitrogen metabolic status and gene expression profile under four different N levels (0×N, 0.1×N, 1×N and 5×N). The plant height and dry weight increased with increasing N levels, whereas an opposite trend was observed for the root length, which decreased with increasing N levels. The leaf SPAD value, stem nitrate concentration, soluble proteins, photosynthetic rate, stomatal conductance and total nitrogen concentration increased with increasing N levels, whereas an opposite trend was observed for soluble carbohydrates and carbon/nitrogen ratio which decreased with increasing N levels. Metabolite profile analysis revealed that the low N treatment caused visible decreases in the concentrations of total sugars and organic acids in the leaves, while caused visible increases in the concentrations of total sugars, organic acids and free amino acids in the roots. Gene expression analysis showed that the transcriptional levels of 5 genes (GS1;3, NADH-GOGAT1, NADH-GOGAT2, PEPC4 and PEPC7) altered significantly under four different N levels.

Flooding tolerance in maize (Zea mays subsp. mays) F1 hybrids containing a QTL introgressed from teosinte (Zea nicaraguensis)

Worldwide climate change has increased the risk of crop yield losses caused by flooding. Here, we report the development of maize F1 hybrids containing a teosinte QTL for flooding tolerance on chromosome 4 and the evaluation of flooding tolerance under reducing soil conditions. We used F1 hybrid Mi29 × Mi47 (cultivar Yumechikara) and two versions of Yumechikara into which the QTL has been introgressed, Mi47 × IL#18 (heterozygous for the QTL) and IL#18 × BC3#90 (homozygous for the QTL). Flooding tolerance was evaluated at three treatment levels (i.e., soluble starch at 1, 0.5 or 0 g L−1) and the non-flooded control at an early growth stage (2.6- to 3.0-leaf stage) and at the 5.5-leaf stage. Tolerance was assessed by measuring leaf injury, leaf SPAD values, and shoot and root dry weight ratios (treatment/control). The F1 hybrids containing the QTL were significantly more tolerant (as evaluated by leaf injury and SPAD values) than the original F1 cultivar (Mi29 × Mi47) at both growth stages. When flooding tolerance was evaluated by shoot dry weight ratio at an early growth stage, IL#18 × BC3#90 was significantly more tolerant than Mi29 × Mi47 at the 1 and 0 g L−1 treatment levels. At the 5.5-leaf stage, there were no significant differences among the three F1 hybrids under the three treatment levels. Although plants at an early growth stage are generally more sensitive to flooding than at later stages, IL#18 × BC3#90 should overcome flooding stress at the sensitive early stage of growth.

Effects of Living Mulch and Fertilizer on the Performance of Broccoli in Plasticulture

Living mulch systems allow cover crops to be grown during periods of cash crop production, thereby extending the duration of cover crop growth and associated beneficial agroecosystem services. However, living mulches may also result in agroecosystem disservices such as reduced cash crop yields if the living mulch competes with the crop for limiting resources. We examined whether the effects of an Italian ryegrass [Lolium multiflorum (Lam.) Husnot]–white clover (Trifolium repens L., cv. New Zealand) living mulch on broccoli (Brassica oleracea L. var. italica) yield and yield components were dependent on fertilizer rate in field experiments conducted in Durham, NH, in 2011 (Expt. 1) and 2012 (Expt. 2). Drip-irrigated broccoli was grown under a range of organic fertilizer application rates in beds covered with plastic, with and without a living mulch growing in the uncovered, interbed space. Broccoli yields were similar in the living mulch and bare soil controls under the highest rates of fertilizer application in Expt. 1. In Expt. 2, living mulch reduced broccoli yields from 28% to 63%, depending on fertilizer rate. Differences in leaf SPAD values suggest that yield reductions were attributable, in part, to competition for nitrogen; however, other factors likely played a role in determining living mulch effects. Despite yield reductions, the living mulch reduced the prevalence of hollow stem in broccoli in Expt. 1. Organic fertilizer may have inconsistent effects on broccoli yields in living mulch systems.

Does Thinning of Old Apple Trees Improve Fruit Quality and Decrease Pest Incidence?

The effect of thinning on fruit weight, color, biochemical composition, and on leaf insect occurrence was studied in an over 80-year-old orchard on two apple tree (Malus domestica Borkh.) old cultivars: Liivi Sibulõun and Paide Taliõun. The study was conducted to restore an old orchard for quality apple juice production. Pruning led to a significant increase in pests, but the number of natural enemies of pests and of neutral insects did not increase. The total number of arthropods was significantly higher on ‘Paide Taliõun’ in the second year after pruning. Consequently, more pests were found in both experimental years on this cultivar. Pruning significantly increased leaf SPAD value leading to a decrease in the total phenolics content of the fruit. The effect of thinning on ascorbic acid content was cultivar dependent. Fruit skin was greener, apple flesh color was yellower, and fruit weight increased by up to 60% after pruning. Among apple taste parameters, the sugar acidity ratio was not influenced by pruning but was positively correlated with skin color, especially in ‘Liivi Sibulõun’. Thinning of old apple trees does not affect the taste of apples but could reduce the impact on the healthy parameters, such as phenolic compounds.

Accumulated expression level of cytosolic glutamine synthetase 1 gene (OsGS1;1 or OsGS1;2) alter plant development and the carbon-nitrogen metabolic status in rice.

Maintaining an appropriate balance of carbon to nitrogen metabolism is essential for rice growth and yield. Glutamine synthetase is a key enzyme for ammonium assimilation. In this study, we systematically analyzed the growth phenotype, carbon-nitrogen metabolic status and gene expression profiles in GS1;1-, GS1;2-overexpressing rice and wildtype plants. Our results revealed that the GS1;1-, GS1;2-overexpressing plants exhibited a poor plant growth phenotype and yield and decreased carbon/nitrogen ratio in the stem caused by the accumulation of nitrogen in the stem. In addition, the leaf SPAD value and photosynthetic parameters, soluble proteins and carbohydrates varied greatly in the GS1;1-, GS1;2-overexpressing plants. Furthermore, metabolite profile and gene expression analysis demonstrated significant changes in individual sugars, organic acids and free amino acids, and gene expression patterns in GS1;1-, GS1;2-overexpressing plants, which also indicated the distinct roles that these two GS1 genes played in rice nitrogen metabolism, particularly when sufficient nitrogen was applied in the environment. Thus, the unbalanced carbon-nitrogen metabolic status and poor ability of nitrogen transportation from stem to leaf in GS1;1-, GS1;2-overexpressing plants may explain the poor growth and yield.

RELATIONSHIP BETWEEN MANGOSTEEN LEAF NITROGEN CONTENTS AND LEAF SPAD VALUES

We investigated nitrogen contents on mangosteen leaf and related on leaf SPAD value. The experiment was conducted using mangosteen trees grown in commercial orchard in Bogor, Indonesia during May to October 2010. Mangosteen trees of 3 different ages, young (20-year-old), middle-aged (35-year-old), and old (50-year-old) trees, each of five trees, were selected for study, and the canopy of each tree was divided into 9 sectors based on height (bottom, middle, top) and width (inner, center, outer). SPAD values had a negative correlation with leaf N content in all ages and could be explained by regressionl equations N level (% DW) = -0.0099 × SPAD + 2.2366; R² = 0.91; N level (% DW) = -0.0177 × SPAD + 2.8001; R² = 0.67; and N level (% DW) = -0.0187 × SPAD + 2.7785; R² = 0.45 in young, middle-aged and old trees, respectively. It is suggested that the SPAD value determined by a portable chlorophyll meter can be used to obtain a quick estimation of mangosteen leaf N status. Keywords: age, fruiting position, Garcinia mangostana L., nitrogen, SPAD

CO2및 기온 상승이 '후지'/M.9 사과나무의 광합성, 신초생장 및 과실품질에 미치는 영향

This study was conducted to find out the influence of elevated atmospheric CO2 concentrations and air temperature on photosynthesis and fruit quality of ‘Fuji’/M.9 apple trees and to investigate these to the effects of climate change during the last four years (2009-2012). The treatments employed were: ‘Ambient’ (ambient temperature + ambient CO2 concentration); ‘High CO2’ (ambient temperature + elevated CO2 concentration); ‘High Temp.’ (elevated temperature + ambient CO2 concentration); and ‘High CO2 + High Temp.’ (elevated temperature + elevated CO2 concentration). The elevated temperature plots were maintained at 4 o C higher than ambient air temperature, while the elevated CO2 plots were maintained at 700 µmol·mol �1 . Annual treatment period was applied from end of April to beginning of November for four years. Results showed that elevated CO2 decreased stomatal conductance and leaf SPAD value, but increased photosynthetic rate, intercellular CO2 concentration (Ci), and starch content of mesophyll tissue. In the vegetative growth, elevated temperature increased total number of shoot and total shoot growth per tree, but elevated CO2 decreased average shoot length. In the fruit quality, elevated CO2 increased soluble solid content, fruit red color, and ethylene production. In conclusion, elevated CO2 increased photosynthetic rate of apples during the early growth, but effect of increased photosynthetic rate due to elevated CO2 was decreased during latter growth stage. Elevated temperature, on the other hand, tended to decrease photosynthetic rate of apples during the early growth, but that tended to increase during latter growth stage. Both elevated CO2 and temperature tended to decrease the degree of decreased photosynthetic rate due to each factor.

Effects of Different Cultivation Patterns on Population Quality of Japonica Hybrid Rice

A high quality of population is necessary to achieve high grain yield in rice, but little information is available on understanding how cultivation patterns affect population quality. In this study, two japonica hybrid rice cultivars Changyou 3 and Changyou 5 were grown in the field, with six cultivation patterns including no nitrogen application (0N), local high yielding cultivation (control), cultivation for high yielding and high efficiency (CHYHE), super high yielding cultivation (SHY), cultivation for super high yielding and high efficiency (SHYHE) and cultivation for high use efficiency of N (HUEN). The results showed that, the average yields of two cultivars under SHY and SHYHE were 12.0 t ha –1 and 10.9 t ha –1 , respectively, and 41.6% and 29.1% higher than these of control. Compared with the control, the SHY and SHYHE also significantly increased percentage of productive tillers, biomass from heading to mature, efficient and high efficient leaf area, grain-leaf ratio, leaf photosynthetic rate and SPAD values after anthesis , root-shoot ratio, and root bleeding after heading. The results indicated that the population quality of rice could be improved and higher yield could be achieved through integrating and optimizing cultivation techniques in rice production.

Comparing SPAD and atLEAF values for chlorophyll assessment in crop species

Zhu, J., Tremblay, N. and Liang, Y. 2012. Comparing SPAD and atLEAF values for chlorophyll assessment in crop species. Can. J. Soil Sci. 92: 645–648. This research had the objective of determining whether a new light transmittance meter, the atLEAF, could be used as a less expensive alternative to the SPAD meter. Both meters measure transmittance through leaf surfaces in wavelengths associated with chlorophyll, and both provide an indirect method for determining the nitrogen status of crop canopies. The current study compared SPAD and atLEAF values under different conditions and for six crop species (canola, wheat, barley, potato and corn). The results indicated strong correlations among laboratory leaf chlorophyll (Chl) content, SPAD values, and atLEAF values. Equivalent performances were observed for SPAD and atLEAF values in different environments regardless of crop species. Therefore, the atLEAF Chl meter can be used as an inexpensive alternative to the SPAD-502 meter.

Comparing SPAD and atLEAF values for chlorophyll assessment in crop species

Zhu, J., Tremblay, N. and Liang, Y. 2012. Comparing SPAD and atLEAF values for chlorophyll assessment in crop species. Can. J. Soil Sci. 92: 645-648. This research had the objective of determining whether a new light transmittance meter, the atLEAF, could be used as a less expensive alternative to the SPAD meter. Both meters measure transmittance through leaf surfaces in wavelengths associated with chlorophyll, and both provide an indirect method for determining the nitrogen status of crop canopies. The current study compared SPAD and atLEAF values under different conditions and for six crop species (canola, wheat, barley, potato and corn). The results indicated strong correlations among laboratory leaf chlorophyll (Chl) content, SPAD values, and atLEAF values. Equivalent performances were observed for SPAD and atLEAF values in different environments regardless of crop species. Therefore, the atLEAF Chl meter can be used as an inexpensive alternative to the SPAD-502 meter.

不同产量水平旱地冬小麦品种干物质累积和转移的差异分析

PDF HTML阅读 XML下载 导出引用 引用提醒 不同产量水平旱地冬小麦品种干物质累积和转移的差异分析 DOI: 10.5846/stxb201106120775 作者: 作者单位: 西北农林科技大学资源环境学院,西北农林科技大学资源环境学院,西北农林科技大学资源环境学院,西北农林科技大学资源环境学院,西北农林科技大学资源环境学院,西北农林科技大学资源环境学院 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金(30871596);农业公益性行业科研专项经费项目(200803030); 现代农业产业技术体系建设专项资金 Analysis of dry matter accumulation and translocation for winter wheat cultivars with different yields on dryland Author: Affiliation: College of Resources and Environmental Science, Northwest A&F University,College of Resources and Environmental Science, Northwest A&F University,,,, Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:旱地小麦高产栽培中品种起着重要作用,研究不同产量水平旱地冬小麦品种干物质累积和转移的差异,对黄土高原旱区作物高产稳产有重要意义。以9个旱地冬小麦品种为材料,通过田间试验研究了不同产量水平旱地冬小麦品种的生物量、花前花后干物质累积量、干物质转移量、转移率及转移干物质对籽粒的贡献率、叶面积、SPAD值以及光合速率的差异。结果表明,不同小麦品种的生物量、花前花后干物质累积量、干物质转移量、转移率及转移干物质对籽粒的贡献率均存在明显差异。与不施肥相比,高、中、低3个产量水平小麦品种在低养分投入时,成熟期生物量分别提高29%,22%和6%,高水平时分别提高46%,39%和23%,高产品种的生物量及其对养分投入的敏感程度明显高于低产品种。不同品种的花后干物质累积量随养分投入水平提高而增加,但花前营养器官中储存物质的转移量、转移率和对籽粒的贡献率却明显随之下降。功能叶(旗叶)在灌浆期高、中、低3个产量水平品种的SPAD值在低养分投入条件下分别为20.7、17.5和13.7;高养分投入时,分别为35、26.1和16.8。高产品种西农88的光合速率为6.0 μmolCO2·m-2·s-1),中产和低产品种的平均光合速率分别为4.3 μmolCO2·m-2·s-1和4.0 μmolCO2·m-2·s-1,高产品种功能叶(旗叶)在灌浆期能保持较高的SPAD值和光合速率,因而花后能生产较多的干物质,但其花前干物质转移量、转移率及转移干物质对籽粒的贡献率均没有明显优势。可见,花后较高的叶绿素水平、光合速率和干物质累积是旱地小麦品种高产的重要原因。选择优良品种,采取合理的栽培措施, 特别是通过养分调控保持花后具较高的干物质累积量是西北旱地进一步提高冬小麦产量的重要途径。 Abstract:Located mainly in the dryland areas, the Loess Plateau is an important region for crop production with winter wheat (Triticum aestivum L.) as a major crop all over the lands. In cropping systems, winter wheat cultivars play an important role. For obtaining high and stable wheat yields in the region, it is of significance to select the most suitable variety of winter wheat for practical use and reveal the differences of dry matter accumulation and translocation of the winter wheat cultivars with various-yielding levels for understanding of their internal characteristics. For this purpose, a field experiment was conducted from 2008 to 2009 in a site where no fertilizer had been received for six years before the trial. Two factors were included in the experiment: wheat cultivars and fertilization. Nine wheat cultivars with different yield levels released and widely adopted in the region were utilized as testing materials and each was planted at three nitrogen and phosphate input rates with four replications. During plant growth period, plants were sampled at flowing and harvest stages and the total dry matter amounts and the dry matter accumulation pre- and post-anthesis were measured so that the differences of dry matter translocation, dry matter transported amount and rate, transferred efficiency as well as the contribution of the transferred dry matter to grains could be evaluated for those winter wheat cultivars. In addition, the leaf area, SPAD value and photosynthetic rate were also determined at some stages for further illustrating the yield-forming traits. The leaf area was measured at booting stage by LI-3000A leaf area instrument, the SPAD at both booting and grain filling stages by SPAD device, and photosynthetic rate at grain filling stage by LI-6400 portable photosynthetic instrument. The results showed that dry matter, dry matter accumulation during pre-anthesis and post-anthesis, dry matter transferred efficiency and the contribution of transported dry matter to grain yield were significantly different for different winter wheat cultivars. Compared to the control without fertilization, the total accumulation productions of the high, middle and low yielding cultivars were 29%, 22% and 6% increased for the low fertilizer input treatment, and 46%, 39% and 23% for the high fertilizer input treatment, respectively. With the increase of fertilizer rate, the dry matter accumulation in the post-anthesis was increased for the different yielding cultivars whereas, the dry matter translocation, transferred efficiency and the contribution of the transferred dry matter to grain yield were decreased. At the grain filling stage, the SPAD value of their functional leaves or flag leaves of high, middle and low yielding cultivars was 20.7, 17.5 and 13.7 for the low fertilizer input treatment, while 35, 26.1 and 16.8 for the high fertilizer input treatment, respectively. The photosynthetic rate of high yielding cultivars (Xinong 88) was 6.0 μmolCO2·m-2·s-1 whereas the average photosynthetic rates of middle and low yielding cultivars were 4.3 and 4.0 μmolCO2·m-2·s-1, respectively. The high-yielding variety was characterized with high levels of total dry matter production and also with high dry matter accumulation after anthesis. The high dry matter increase after anthesis might be related with the high SPAD value and high photosynthetic rate of the functional leaves during the grain filling stage. In summary, the higher level of SPAD value, photosynthetic rate and dry matter accumulation after anthesis was one important reason for wheat cultivars with high grain yields on drylands of the Loess Plateau. Therefore, selecting qualified wheat cultivars, adopting adequate cropping measures as general, and especially maintaining a high dry matter accumulation during post-anthesis through the regulation of nutrient management could be regarded as the essential ways for further improvement of winter wheat yield production in the area. 参考文献 相似文献 引证文献

Population-specific quantitative trait loci mapping for functional stay-green trait in rice (Oryza sativaL.)

The functional stay-green trait gives leaves a longer duration of greenness and photosynthetic capacity during the grain-filling period. We developed two independent recombinant inbred line populations from the intra- and intersubspecific crosses of Oryza sativa L. subsp. japonica 'Suweon490' (japonica) × O. sativa subsp. japonica 'SNU-SG1' (japonica) and O. sativa subsp. indica 'Andabyeo' (indica) × O. sativa subsp. japonica 'SNU-SG1' (japonica), respectively. The common parental line 'SNU-SG1' was the functional source for the stay-green trait. Quantitative trait locus (QTL) mapping based on simple sequence repeat markers identified a total of six QTLs associated with two stay-green traits across two populations. The two traits were cumulative chlorophyll content (SPAD value) of flag leaf (CSFL) and total cumulative SPAD value of the four upper leaves (TCS). Four QTLs, tcs4, csfl6, csfl9 (or tcs9), and csfl12, located on chromosomes 4, 6, 9, and 12, respectively, were detected simultaneously in both populations. The remaining two QTLs, csfl2 (or tcs2) and tcs5, on chromosomes 2 and 5, respectively, were found to be population specific. Moreover, the functional stay-green trait of 'SNU-SG1' positively correlated with grain yield performance. Two yield QTLs, yld6 and yld9, on chromosomes 6 and 9 found in both populations were positioned at the same locations with the csfl6 and tcs9 QTLs for stay-green traits. Thus, the identified chromosomal regions can be promising targets of marker-assisted introgression of the functional stay-green trait into breeding materials for improvement of rice yield.