Variation Laws of Anthocyanin Content in Roots and Their Relationships with Major Economic Traits in Purple-Fleshed Sweetpotato [Ipomoea batatas （L.） Lam]

Variation laws of anthocyanin content in root during the development and among the varieties, and their relationships with major economic traits in purple-fleshed sweetpotato [Ipomoea batatas （L.） Lam] were studied in the present article. The dynamics of 20 economic traits in 13 purple-fleshed sweetpotato varieties at 20, 40, 60, 80, 100, 120, and 140 d after their transplanting were investigated, and these traits included anthocyanin content in root, length of the longest vine, number of base branches, root number, dry matter contents in stem, foliage and root, fresh/dry weight of root, fresh/dry weight of stem, flesh/dry weight of foliage, flesh/dry weight of stem and foliage, flesh/dry weight of whole plant, and rations of photosynthate to root, stem, and foliage. The correlations between the variations of anthocyanin content and the other 19 economic traits among varieties and during the whole developing stages, and the correlations of daily increase of anthocyanin content with other l0 kinds of yields were analyzed. The results showed that： （1） During the whole development, the anthocyanin content had three variation types, i.e. a slow-increase type, a fluctuating-change type, and a deviousrising type, and had different responses to the growth of length of the longest vine, number of base branches, flesh/dry yield of root, and photosynthate allotments. （2） The anthocyanin contents among 13 varieties began to have significant difference after 20 d, and showed completed differentiation during 40-100 d, which had significantly negative correlationships with the number of base branches, fresh/dry yield of root, photosynthate allotment ratio to root, and had significant positive correlationships with dry matter content of root, length of the longest vine, fresh/dry yield of stem, dry yield of whole plant and photosynthate allotment ratio to foliage. （3） Because of the significantly negative correlation between daily increase of anthocyanin content and dry matter weight of root, the anthocyanin a     

Characteristics of Rice Plant with Heavy Panicle

Using 15 indica rice varieties with different panicle weight, some ideal plant type characteristics in heavy panicle type of hybrid rice （HPT） and their relation to yield and its components were studied. Results showed that the leaf area index （LAI） of the HPT varieties was lower than that of medium panicle type （MPT） and light panicle type （LPT） varieties, but its decreasing rate of LAI and efficient LAI after heading was slower and had much higher percentage of efficient LAI, specific leaf weight, and ratio of grain to leaf area （cm^2） in comparison with the MPT and the LPT varieties. The length, width, thickness, and area of top three leaves of the HPT varieties were significantly larger than those of the MPT and the LPT varieties, and these components of top three leaves were significantly and positively correlated with the number of spikelets and filled grains, grain weight per panicle, and grain yield. The flag leaf in HPT varieties was erect with sorrow leaf angle, and their leaf angle of 2nd and 3rd leaf from top increased in sequence. The plant height of the HPT varieties was higher than that of the MPT and the LPT varieties, and their leaf site of top three leaves also increased in sequence. Therefore, HPT varieties as an ideal plant type could increase the utilization efficiency of sunlight energy. The ideal plant type characteristics and their adjuncts for the HPT varieties are proposed in this article.     

Comparisons of Photosynthetic Characteristics in Relation to Lint Yield Among F_1 Hybrids,Their F_2 Descendants and Parental Lines of Cotton

We compared the photosynthetic characteristics in relation to yield of two F1 cotton hybrids（Shiza 2-F1 and Xinluzao 43-F1）, their parental lines（NT2, H2 and 4-14） and their F2 descendants at different growth and development stages. The two F1 exhibited heterobeltiosis in net photosynthetic rate（Pn） by 8.1-52.1%, canopy apparent photosynthetic rate（CAP） by 8.2-57.6% and canopy respiration rate（CR） by 3.0-78.7% during the growing season. They also exhibited mid-parent heterosis by 2.0-5.2% in leaf chlorophyll content（SPAD） during the late growth and development stages. Regression analysis showed that both parents contributed to increase in Pn, SPAD and CAP in the F1. A low CR in the F1 matched a low CR of the parental line. Photosynthetic characteristics in the F2 were mainly dependent upon the magnitude and degeneration rate of the F1. Mid-parent heterosis in CAP and in CR during the late growth and development stage reduced the degeneration of the F2. Average dry matter accumulation was 10.7-34.7% higher in the parental lines of Xinluzao 43-F1 than in the parental lines of Shiza 2-F1. Heterobeltiosis in dry matter accumulation was 7.0-23.1% greater for Xinluzao 43-F1 than for Shiza 2-F1. Dry matter accumulation in the F1 was affected by either the dry matter accumulation of parents or heterobeltiosis. Dry matter accumulation in the F2 was mainly influenced by dry matter accumulation in the F1. The yields of the two F1 were 39.1-46.3% higher than their respective parents and 26.4-45.9% higher than that of the conventional cultivar Xinluzao 33. The yields of the two F2 were 9.2-12.8% higher than the parents and 14.9-27.4% higher than that of Xinluzao 33. The photosynthetic production and yield of the F1 and F2 were higher than that of their parents. The increases in Pn and CAP of the F1 and F2 were dependent on the photosynthetic characteristics of their parents. It is thus concluded that the photosynthetic performance, light use efficiency and yield of the F1 can be improved by using at le     

Absorption,Accumulation and Distribution of Zinc in Highly-Yielding Winter Wheat

Zinc（Zn） is an important essential microelement for wheat.In order to study the characteristics of Zn absorption,accumulation and distribution in highly-yielding winter wheat（with a grain yield of 9 000 kg ha-1）,field experiments were conducted in Gaocheng County of Hebei Province,China.Four winter wheat cultivars,i.e.,Shimai 14,Jifeng 703,Shimai 12,and Shixin 828,and four cultivars,i.e.,Temai 1,Shimai 12,Shixin 531,and Shixin 828,were used in the experiment,during 2004-2005 and 2005-2006,respectively.Plant samples were taken from the plots at each growing stage for Zn concentration analysis.The main results showed that the concentration of Zn in various above-ground organs of wheat was 9.5-112.5 mg kg-1 at different growing stages.The organ with the highest Zn concentration differed with the change of growth center at different growing stages.Accumulation of Zn in leaf blades was the highest among all the organs during early growing period,and more than 50% of the Zn accumulation was distributed to leaf blades before jointing,and higher than that to other organs.In late growing period,however,the accumulation of Zn in grains was the highest,and 58.1% of the Zn accumulation was distributed in grains at maturity.The total accumulation of Zn in wheat plant during its life span ranged from 384.9 to 475.9 g ha-1.The amount of Zn required for the formation of 100 kg grain yield ranged from 4.3 to 5.2 g.All the organs were ordered in such a sequence that leaf blades 〉 spikes 〉 leaf sheaths 〉 stems according to their net absorption and transportation of Zn as well as their contribution to Zn accumulation in grains.58.2-60.3% of the Zn accumulated in grains was redistributed from other organs,mostly from leaf blades.Concentration and accumulation of Zn in all the organs of wheat was high during early and middle growing periods,while accumulation of Zn in grains during late growing period mainly depended on the redistribution from other organs.According to these characteristics of Zn absorption and accumulation,Zn should be applied as seed dressing or basal fertilizer,so as to accelerate the early growth and Zn absorption of wheat.     

Selection of Parents for Breeding Edible Varieties of Sweetpotato with High Carotene Content

Sweetpotato varieties with high carotene content have high value for human health. This work aims to improve the breeding efficiency of special varieties with high carotene content by combining molecular markers and agronomic traits to evaluate and screen the parents. The cluster analysis was carried out to identify and screen promising parents by utilizing phenotypic results of the agronomic and characteristic traits, and RAPD and ISSR markers of 15 parents and their offspring by group crossing. Among different parental materials, greater variations were observed in two important traits, the carotene content and the storage root yield. Negative correlation was found between the carotene content and both fresh and dried root yields. The most significant positive correlation was between the carotene content of parents and that of their offspring, with the coefficient of correlation value of 0.7932＊＊. The relationship based on the agronomic characters of the trial materials was not in agreement with the known genealogy, while that based on the molecular marker data showed better result. Each primer amplified 13.8 bands oflSSR markers on average, in which the rate of polymorphic loci was 89.6%. 9.4 bands of RAPD markers were arnplified per primer, in which the rate of polymorphic bands was 74.46%. Large genetic variation of carotene content was found among the parents. For analyzing the genetic diversity of sweetpotato, the molecular marker methods were better than morphological traits; ISSR markers were more efficient than RAPD markers. The combination of molecular markers and agronomic trait analysis may provide valuable theoretic basis for selection of parents to breed new varieties with high carotene content.     

Effect of Season,Location, Cultivar and Spacing on Yield and Quality of Sugarcane in Western Kenya

In Kenya almost all sugarcane grown is under rainfall conditions that are planted in different locations during both long and short rainy seasons. Effect of season, location, cultivar and spacing on yield and quality of sugarcane is not clearly understood. The research was conducted at Kibos and Mumias to determine if the yields and quality of three sugarcane cultivars were affected by season, location and row spacing. Cultivars CO 945, EAK 73-335 and KEN 83-737 were manually planted during June and September in 2011. The trial was laid out as split-split plot arranged in a randomized complete block design （RCBD） replicated three times. Data collected at harvest, 17 months after planting （MAP） including cane yields, cane yield components and cane quality. The results revealed that cane length differed significantly between June and September. Stalk population and cane yields were significantly more at Mumias compared to Kibos. Cultivar EAK 73-335 showed significantly more cane yield （t/ha） than KEN 83-737 and CO 945. Both row spacing 1.2 m and 1.5 m did not affect cane yields. Brix%, Sucrose% and Purity% differed significantly between cultivars. The relationship between cane yield and stalk population was positive and significant, which indicated stalk population is a strong determinant of cane yield. The results showed that cane yield was significantly affected by location and cane quality by cultivars. Therefore Mumias is a better zone for sugarcane cultivation for both June and September seasons compared to Kibos.     

Suitable growing zone and yield potential for late-maturity type of Yongyou japonica/indica hybrid rice in the lower reaches of Yangtze River,China

Late-maturity type of Yongyou japonica/indica hybrids series(LMYS) have shown great yield potential, and are being widely planted in the lower reaches of Yangtze River, China. Knowledge about suitable growing zone and evaluation of yield advantage is of practical importance for LMYS in this region. Fifteen LMYS, two high-yielding inbred japonica check varieties(CK-J) and two high-yielding hybrid indica check varieties(CK-I) were grown at Xinghua(119.57°E, 33.05°N) of Lixiahe region, Yangzhou(119.25°E, 32.30°N) of Yanjiang region, Changshu(120.46°E, 31.41°N) of Taihu Lake region, and Ningbo(121.31°E, 29.45°N) of Ningshao Plain in 2013 and 2014. The results showed that maturity dates of the 15 were later than the secure maturity date at Xinghua and 6, 14 and 15 LMYS were mature before the secure maturity date at Yangzhou, Changshu and Ningbo, respectively. One variety was identified as high-yielding variety among LMYS(HYYS) at Yangzhou, 8 HYYS in 2013 and 9 HYYS in 2014 at Changshu, 9 HYYS at Ningbo. HYYS here referred to the variety among LMYS that was mature before the secure maturity date and had at least 8% higher grain yield than both CK-J and CK-I at each experimental site. Grain yield of HYYS at each experimental site was about 12.0 t ha–1 or higher, and was significantly higher than CK varieties. High yield of HYYS was mainly attributed to larger sink size due to more spikelets per panicle. Plant height of HYYS was about 140 cm, and was significantly higher than check varieties. Significant positive correlations were recorded between duration from heading to maturity stage and grain yield, and also between whole growth periods and grain yield. HYYS had obvious advantage over check varieties in biomass accumulation and leaf area duration from heading to maturity stage. Comprehensive consideration about safe maturity and yield performance of LMYS at each experimental site, Taihu Lake region(representative site Changshu) and Ningshao Plain(representative site Ningbo) were thought suitable growing zones for LMYS in the lower reaches of Yangtze River. The main factors underlying high yield ofHYYS were larger sink size, higher plant height, longer duration from heading to maturity stage and whole growth periods, and higher biomass accumulation and leaf area duration during grain filling stage.     

Effect of SHAKTI and KUBOTA power tillers on physical properties of soil and rice yield under Sawah production system in Nigeria

The use of the power tillers （walking tractors） are increasingly popular in Nigeria among farmers adopting Sawah rice production technology. This study compares the effects of two types of power tillers on physical properties of soil and rice yield. because soil properties determine to a large extents rice yield. Data on soil properties and rice yield were collected and subjected to t-test statistics. The results show that, significant differences exit for all the physical properties of soils rice yields from fields where the two power tiller were used with yields from rice field where SHAKTI was used was higher than KUBOTA. It is important that farmers using these models of power tillers for rice production should not only focus on the purchase cost of these power tillers but their overall efficiency in order to achieve the desired high level of yield.     

Analysis on Major Agronomic Traits and Yield of Huayu Series of Peanut Cultivars under Mulched Drip Irrigation

Objective] This study aimed to investigate the appearance of major agronomic traits and yield potential of Huayu se-ries of peanut cultivars under the condition of mulched drip irrigation, so as to provide core parent materials for new peanut cul-tivar breeding in Xinjiang during Thirteenth Five-Year Plan. [Method] A total of 16 peanut cultivars of Huayu series were studied systematical y by field experiment and laboratory analysis. In addition, the main stem height, lateral branch length, pod number per plant, 100-pod weight, 100-kernel weight, pod length, pod width and yield of different peanut cultivar were compared. [Result] Under the condition of mulched drip irrigation, the appearance of major agronomic traits of peanut cultivars in Xinjiang was bet-ter than that in Shandong areas. In Xinjiang, the yields of the peanut cultivars were increased in varying degrees. However, there were some differences in appearance of major agronomic traits, as wel as yield, among different peanut cultivars. Among al the peanut cultivars, the single-plant productivities of Huayu 22, Huayu 28 and Huayu 50 were higher than those of the other cultivars, and the yields of Huayu 33 and Huayu 50 were higher than those of the other cultivars. Meanwhile, the late two culti-vars’ comprehensive traits were excel ent. [Conclusion] In the high-yielding breeding of peanut in Xinjiang, Huayu 33 and Huayu 50 can be used as core parent materials. Under the condition of mulched drip irrigation, their yield potential can be further ex-plored.     

Modeling Dynamics of Leaf Color Based on RGB Value in Rice

This paper was to develop a model for simulating the leaf color changes in rice （Oryza sativa L.） based on RGB （red, green, and blue） values. Based on rice experiment data with different cultivars and nitrogen （N） rates, the time-course RGB values of each leaf on main stem were collected during the growth period in rice, and a model for simulating the dynamics of leaf color in rice was then developed using quantitative modeling technology. The results showed that the RGB values of leaf color gradually decreased from the initial values （light green） to the steady values （green） during the first stage, remained the steady values （green） during the second stage, then gradually increased to the final values （from green to yellow） during the third stage. The decreasing linear functions, constant functions and increasing linear functions were used to simulate the changes in RGB values of leaf color at the first, second and third stages with growing degree days （GDD）, respectively; two cultivar parameters, MatRGB （leaf color matrix） and AR （a vector composed of the ratio of the cumulative GDD of each stage during color change process of leaf n to that during leaf n drawn under adequate N status）, were introduced to quantify the genetic characters in RGB values of leaf color and in durations of different stages during leaf color change, respectively; FN （N impact factor） was used to quantify the effects of N levels on RGB values of leaf color and on durations of different stages during leaf color change; linear functions were applied to simulate the changes in leaf color along the leaf midvein direction during leaf development process. Validation of the models with the independent experiment dataset exhibited that the root mean square errors （RMSE） between the observed and simulated RGB values were among 8 to 13, the relative RMSE （RRMSE） were among 8 to 10%, the mean absolute differences （da） were among 3.85 to 6.90, and the ratio of da to the mean observation values （Clap） were among 3.04 to 4.90%. In addition, the leaf color model was used to render the leaf color change over growth progress using the technology of visualization, with a good performance on predicting dynamic changes in rice leaf color. These results would provide a technical support for further developing virtual plant during rice growth and development.     

叶菜型甘薯蔓尖产量构成分析

1材料与方法1．1材料7个叶菜型甘薯品种：莆薯53、广菜薯1号、广菜薯2号、阜菜薯1号、福薯10号、福薯11号、福薯7-6。1．2方法试验地点设在西南大学重庆市甘薯研究中心北碚农科所基地内,紫色黏土,肥力中上。2006年和2007年均按随机区组排列设计,设3次重复。每小区畦作6行,     

甘薯叶菜型品种蔓尖产量构成分析

对7个甘薯叶菜型品种2006~2007年的蔓尖产量和叶片、叶柄、茎占蔓尖产量的比例及其在品种与不同采收期间的变化的研究表明:甘薯蔓尖产量在不同的品种和采收期间有显著差异,叶片占蔓尖产量的50%左右,它在采收期间的变化大于品种间的变化,而叶柄和茎各占25%,它在品种间的变化大于采收期间的变化。由于叶片营养成分高于叶柄和茎,因此,叶片在蔓尖的产量和品质中占有重要地位。对甘薯叶菜型品种蔓尖产量构成的分析为甘薯叶菜型专用品种的选育、栽培和产业化提供了一定的科学依据。     

不同叶菜型甘薯品种茎尖绿原酸含量及清除DPPH·能力

【目的】研究叶菜型甘薯茎尖绿原酸的含量及其清除DPPH·能力,为叶菜型甘薯的品种筛选、栽培及产业化提供理论依据。【方法】在6个不同生长期分别采收广菜薯2号、莆薯53和福薯7-6的茎尖,测定并分析茎尖叶片、叶柄和茎绿原酸含量及其与DPPH·清除能力之间的相关性。【结果】(1)6次采收期的不同甘薯品种茎尖绿原酸平均含量大小为:广菜薯2号(0.2920%fb)莆薯53(0.2750%fb)福薯7-6(0.1638%fb),其中叶片(0.3539%fb)茎(0.1444%fb)叶柄(0.1173%fb),叶片含量是叶柄和茎平均值的2.70倍;广菜薯2号、莆薯53和福薯7-6茎尖前3个采收时期绿原酸的平均含量分别是后3个时期的2.22、2.68和2.41倍,其中叶片、叶柄和茎前3次采收期绿原酸含量的平均值分别是后3次采收期的2.49,2.53和2.20倍。差异均达到显著水平。(2)根据3个品种6次采收期的平均值计算,叶片对茎尖绿原酸含量的贡献率为73.64%,叶柄为11.96%,茎为14.41%。(3)茎尖6次采收期的DPPH·清除能力平均大小为:广菜薯2号(34.99%)莆薯53(31.05%)福薯7-6(18.83%),其中叶片(32.52%)茎(23.64%)叶柄(17.91%);前3个采收时期的茎尖、叶片、茎和叶柄的DPPH·平均清除能力分别是后3个时期的1.91、2.02、1.69和1.99倍。【结论】叶菜型甘薯茎尖绿原酸含量在品种、部位和采收期间有显著差异;DPPH·清除能力与绿原酸含量具有显著或极显著正相关。因此,在叶菜型甘薯品种选育、栽培和产业化过程中要充分考虑茎尖绿原酸含量的变化特点。     

紫肉甘薯花色苷含量的变化规律及其与主要经济性状的相关分析

 【目的】研究紫肉甘薯块根花色苷含量在生育过程中和品种间的变化规律及其与主要经济性状的相关性。【方法】栽插后20、40、60、80、100、120及140 d调查13个紫肉甘薯品种的花色苷含量、最长蔓长，分枝数，结薯数，茎、叶、块根干物质含量，块根鲜重, 块根干重，茎鲜重、茎干重、叶鲜重、叶干重，茎叶鲜重、茎叶干重，分析整株鲜重、整株干重，茎、叶、块根干重占整株干重的百分比等20个经济性状以及花色苷含量变化与其余19个经济性状的变化和10个产量性状日增长量的相关性。【结果】（1）紫肉甘薯块根花色苷含量在生育过程中存在缓慢增加型、波动变化型和曲折上升型3种变化类型, 对最长蔓长、分枝数、块根鲜重、块根干重、光合产物的分配等经济性状的发育有不同的生物学响应。（2）品种间的花色苷含量在20 d以后逐渐产生显著差异，在40～100 d完成类型分化, 与品种的分枝数、块根鲜重、块根干重、光合产物在块根中的分配比例显著负相关，与块根干物质含量、最长蔓长、茎鲜重、茎干重、整株干重及光合产物在叶中的分配比例显著正相关。（3）花色苷日增长量与块根干重日增长量显著负相关，花色苷积累与块根膨大、干物质积累存在竞争关系，这种竞争关系在不同品种中得到不同解决。【结论】由于花色苷积累与干物质积累存在的竞争关系在不同品种中的协调不同，紫肉甘薯品种间的花色苷含量在生育过程中产生显著差异和分化，存在缓慢增加、波动变化和曲折上升3种变化类型。花色苷含量的这些变化与主要经济性状有不同的相关关系。     

Evaluation of the Characteristics of Virus-free Sweetpotato and Its Use in Hybridization

Application of virus-free sweetpotato is a breakthrough of sweetpotato production. Several popular varieties were adopted to study their yield increase potential and their use in breeding in this research.The results showed that after virus-elimination, all varieties had a yield increase ranging from 14.95% -91.61% and marketable quality improvement, despite the changes in location and season. The changes of dry matter content and disease resistance were not significant. Virus-free sweetpotato performed vigorous vine growth and strong dry matter assimilation ability. Virus-free parents had a slightly high seed setting percentage, but its flowering ability and performance of off-springs were similar to that of its check plants.     

甘薯苗期耐低氮基因型筛选及不同氮效率类型综合评价

【目的】建立甘薯品种（系）耐低氮能力评价体系,筛选耐低氮基因型甘薯材料和评价不同氮效率类型,为研究耐低氮甘薯生理机制和挖掘氮高效基因奠定基础。【方法】采用水培试验,以来自国内外不同薯区的126份甘薯品种（系）为材料,低氮胁迫（0 mmol·L^-1纯氮）和正常施氮（14 mmol·L^-1纯氮）处理下,收集126个品种（系）地上干重、地上干物质增加量、地下干物质增加量、总干物质增加率、根冠比、蔓长、根长、叶数、叶绿素相对含量（CCI）、氮积累量和氮素生理利用效率11个性状表征值,计算各指标耐低氮胁迫指数。利用综合隶属函数法,进行主成分分析、回归分析和聚类分析,综合评价各甘薯品种耐低氮能力和氮效率类型。【结果】1）低氮水平条件下,不同供试甘薯品种（系）的地上干重、地上部干物质增加量、地下部干物质增加量、总干物质增加率、根长、蔓长、叶数、CCI、氮素积累量的均值低于正常氮处理,根冠比和氮素生理利用效率的均值高于正常氮处理;2）不同品种（系）的地上干重、地上部干物质增加量、地下部干物质增加量、总干物质增加率、根冠比、根长、蔓长、叶数、氮素积累量和氮素生理利用效率的变异系数高于正常氮处理,且其增幅排序为地上干物质增加量>总干物质增加率>地下干物质增加量>叶数>地上干重>氮素生理利用效率>氮积累量>根长>根冠比>蔓长;3）对11个指标的耐低氮胁迫指数进行主成分分析,3个主成分的累计方差贡献率达到72.67%,计算综合评价值Y;4）地上干重、地上部干物质增加量、地下部干物质增加量、总干物质增加率、叶数、蔓长、根长、根冠比、氮积累量、氮素生理利用效率的耐低氮胁迫指数与Y值的相关性达到极显著水平（P<0.01）,其中,地上部干物质增加量、地下部干物质增加量、总干物质增加率、氮积累量和地上干重5项耐低氮胁迫指数的相关性较高,相关系数分别为0.85、0.86、0.81、0.79和0.73;5）建立Y值回归方程,选定耐低氮能力评价的8个指标,并进行系统聚类,划分甘薯基因型为耐低氮型、中间型、不耐低氮型3类;并对3种耐低氮甘薯类型的农艺性状和氮效率性状进行方差分析。【结论】地上干重、地上部干物质增加量,地下部干物质增加量、根长、蔓长、叶数、氮素积累量和氮素生理利用效率作为甘薯耐低氮能力评价的指标;13104-2/紫薯1号、宜宾红心薯、浙紫薯2号、渝紫3号、渝紫6号、漯紫1号和渝紫香10号7个为耐低氮型甘薯品种;耐低氮型品种的各性状表现好于中间型和不耐低氮型,其中,地上干重、地上部干物质增加量、地下部干物质增加量、蔓长和氮积累量差异显著。     

叶菜型甘薯栽培技术及施氮安全研究

为了探索叶菜型甘薯高产栽培安全施肥技术以及对其进行产业化开发,采用不同种植密度、不同肥料类型、不同施肥水平以及测定作菜食用部分硝酸盐积累情况等试验,初步明确了中长蔓分枝品种适宜种植密度为每公顷30~33万株,短蔓分枝强的品种适宜种植密度为每公顷27~30万株。施足肥料、多施氮肥对提高茎叶产量和茎叶鲜嫩度有明显效果,多施有机肥、拉长追肥间隔期以及优化配方施肥是降低茎叶硝酸盐含量行之有效的措施;而培育壮苗、合理密植、及时采摘、清洁园地、优化施肥、重施基肥以及加强管理、运用水肥促控技术、调节茎叶生长速度是叶菜型甘薯高产栽培与施氮安全关键技术措施。     

甘薯叶片的抗氧化活性和相关成分比较

为了选育保健型菜用甘薯品种,以海南地区栽种的10个甘薯品种为材料,对叶片中3种色素（花青素、叶绿素、类胡萝卜素）、总酚和总黄酮含量进行测量,通过分析各指标与代表抗氧化性的ABTS（2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)、2,2′?联氮?双?3?乙基苯并噻唑啉?6?磺酸）、DPPH（2,2′-diphenyl-1-picrylhydrazyl,2,2′?二苯基?2?三硝基苯肼）自由基清除能力的关联性,综合分析甘薯叶片的抗氧化成分及抗氧化活性。结果表明,不同甘薯品种叶片的抗氧化活性与总黄酮、花青素含量呈极显著正相关（P < 0.01）,与叶绿素含量呈显著正相关（P < 0.05）,与总酚含量呈正相关但未达到显著相关水平（P > 0.05）。甘薯‘福薯7-6’的叶绿素和类胡萝卜素含量较高,但总酚、总黄酮和花青素含量低,抗氧化活性最低;‘渝15’和‘徐紫菜8’叶片的总酚、总黄酮和花青素显著高于其他8个品种,抗氧化活性最高。在选育保健型菜用甘薯时,可根据叶片颜色初步判断其抗氧化性能,降低育种成本。     

部分烤烟种质资源在贵州省的初步评价

12份烤烟品种资源的品质鉴定试验结果表明:各参试品种间株型、叶形、叶尖、叶面、叶缘、叶色、叶耳、叶片主脉粗细、叶片厚薄等植物学形态特征和打顶株高、茎围、节距、叶数、叶长、叶宽等主要农艺性状存在明显差异,充分表现了各种质的特征特性;各参试品种间产量、中等烟率和上等烟率差异达极显著水平。