Glycemic Index of a Diabetes-Specific Nutritional Powder: An Open-Label Study in Healthy Indian Adults

Background: A balanced diet with a low glycemic index (GI) plays an important role in controlling and managing type 2 diabetes mellitus (T2DM). Here, we compared the GI of 2 flavors (vanilla and chocolate) of diabetes-specific nutritional (DSN) supplements to its comparator in healthy Indian adults under fasting conditions. Methods: This study was a 39-day open-label, non-comparative, single-center trial involving healthy adults aged between 18 to 45 years. The subjects received equal doses of 2 DSN powder (Treatments A and B), the comparator product (Treatment C), and dextrose monohydrate as a reference (Treatment R). Doses were administered as per the dosing schedule, after an overnight fast for 10 hours, with 2 intervening non-dosing days. Blood samples were collected on the dosing days to assess changes in capillary blood glucose levels. The primary endpoint of the study was the mean GI of Treatments A, B, and C (Defined as low: GI ≤ 55;medium: 55 GI ≤ 70;High: GI > 70), generated using the incremental area under the curve (AUCi) methodology. Safety was assessed throughout the study. Values of all study parameters were represented in ±SD or standard deviation. Results: Fourteen adult male subjects with a mean age of 29.42 ± 4.46 years, and a body mass index of 22.0 ± 1.95 Kg/m2, were enrolled in the study. The mean AUCi for treatments A, B, and C were 104 ± 10, 111 ± 12, and 87 ± 12 mmol min/L, respectively and for Treatment R it was 276 ± 16, 319 ± 28 and 338 ± 25 mmol min/L for Days 1, 6 and 8, respectively. The mean GI of Treatment A was 33 ± 3, Treatment B was 35 ± 3 and Treatment C was 29 ± 5;all GI means were ≤55. Mild adverse events were reported in 2 (14.3%) subjects. No serious adverse events or deaths were reported in the study. All treatments were well tolerated by the subjects. Conclusion: The glycemic index of both test products and comparator was low (i.e., GI 55) as per ISO 26642:2010 standard.

Influences of Different UV-B Radiation Treatments in Short Time on Some Physiological Characteristics of Winter Wheat Seedlings

[Objective] studying the influences of different UV-B radiation treatments in short time on some physiological characteristics of winter wheat seedlings was to provide reference for the mechanism of plant response to ultraviolet irradiation in short time. [Method] The winter wheat taken as materials were treated with 15 and 30 pW/cm^2 UV-B radiation, then the physiological indexes such as pigment content and photosynthetic rate were determined. [ Results] The UV-B treatment caused the declines of chlorophyll content, soluble protein content and water content of leaves, besides, dose-effect was existed. The decline of 30 pW/cm^2 treatment was bigger than that of 15 μW/cm^2 treatment. The influences of UV-B radiation on carotenoid content and anthocyanidin content were similar; the change trends were declined firstly then increased. The UVB treatment with two doses restrained the electron transport of PSⅡ, particularly; the inhibitory effect was biggest after treated 2 h, and then this effect was declined in 4, 6 and 8 h, so the dose-effect was existed. The UV-B radiation with two doses restricted photosynthetic rate and the inhibitory effect increased with the increase of treatment time. The high dose treatment caused huge damage to membrane system, while the result of low dose treatment was not obvious. [ Conclusion] UV-B radiation treatment had dose-effect on winter wheat seedlings in short time and the influence of high dose was bigger than that of low dose. With the increase of treatment time, the damage was alleviated; besides, the result was not similar to that of UV-B radiation in long time.

Effects of sludge on germination and initial growth performance of Leucaena leucocephala seedlings in the nursery

A study was carried out to determine the influence of different types of sludges （municipal, industrial and residential） on field germination, growth and nodulation of L. leucocephala seedlings in the nursery. Before sowing of seeds, different combinations of sludges were incorporated with the nutrient deficient natural forest soils. Field germination, nodulation status and physical growth parameters of seedlings （shoot and root length, vigor index, collar diameter, leaf number, fresh and dry weight of shoot and root and total dry biomass increment） were recorded after three and six months of seed sowing. Field germination, nodulation status and growth parameters were varied significantly in the soil amended with sludges in comparison to control. The highest number of nodule was recorded from soil amended with residential sludge （ 1：1 ） and highest fresh and dry nodule weight was also found from the same combination in both three and six month old seedlings. In case of growth parameters, the highest growth was recorded from soil and residential sludge （ 1：1 ） combination compared to control. From the study, it can be recommended that soil amended with residential sludge （ 1：1 ） provide better field germination, growth and nodule formation of L. leucocephala in degraded soil.

Growth and yield of rice as affected by transplanting dates and seedlings per hill under high temperature of Dera Ismail Khan, Pakistan

Studies were initiated for two consecutive years to find out the effect of time of transplanting and seedlings hill^-l on the productivity of rice in Dera Ismail Khan district of North West Frontier Province （NWFP）, Pakistan. The experiment was laid out in a randomized complete block design with split plot arrangements. Main plots consisted of four transplanting dates viz. 20th and 27th of June and 4th and 1 lth of July while sub-plots contained 1, 2, 3 or 4 seedlings hill^-1. Among transplanting dates, June 20th planted crop gave highest paddy yield and net return with I seedling hill^-1. It explains that the use of more seedlings hill^-1 not only adds to cost but is also a mere wastage of natural resources. Based on research findings, we conclude that the use of I seedling hill^-1 is most appropriate for timely sowing otherwise 4 seedlings hill^-1 should be used to compensate for the yield gap in late transplanted rice.

Effect of 6-BA on Physiological Changes in Two Palm Seedlings Under Varied Temperaures

The effects of 6-benzylaminopurine （6-BA） on several physiological indexes of Caryota mitis and C. obtusa seedlings treated at varied temperatures were conducted, the leaves of the two palm species were sprayed with 0, 25, 50 and 100 mg · L1 6-BA solutions, the activities of superoxide dismutase （SOD）, peroxidase （POD）, and the contents of malondialdehyde （MDA）, proline, soluble protein, chlorophyll and chlorophyll a/b were determined under 25 ℃, 5 ℃ and 25 ℃ for 24 h, respectively. The dynamics of a series of important physiological components derived from the leaves were studied. It was indicated that all the above mentioned physiological indexes varied with different concentrations of 6-BA and temperature. The fuzzy comprehensive evaluation values for different concentrations of 6-BA at the recovery temperature 25℃ were 0.33, 0.28, 0.92 and 0.33, respectively for C. mitis, and 0.20, 0.49, 0.56 and 0.63, respectively for C. obtusa. It was concluded that leaves sprayed with different concentrations of 6-BA could affect the cold tolerance of palm seedlings. The optimal concentration of 6-BA was different for different palm species.

Study on the Export Competitiveness of China's Flower Seedlings

This paper introduces the " National Diamond Model" and reviews the literature concerning the export of flower seedlings.Then it analyzes the production and export of Chinese flower seedlings,as well as the factors( factor endowments,foreign demand,related industries and industrial organization) influencing the production of Chinese flower seedlings based on Diamond Model.Finally,this paper puts forth the recommendations for the enhancement of the export competitiveness of Chinese flower seedlings.

Research on the Synthetic Appraisal Index System of Lake Health

[Objective ] The study aimed at assessing the state of lake health. [ Method] Based on the concept of ＂healthy lakes＂ analyzed deeply, the fuzzy integrated evaluation was used to establish the evaluation index system of lake health, and the analytic hierarchy process （AHP） com- bined with expert evaluation method was used to determine the weight of each indicator. Afterwards, the health state of three typical lakes （ San- baidang, Beimayang and Qiaobeidang） in Wujiang City were evaluated by the system, and the measures to develop and protect the lakes were put forward finally. E Resultl The assessment results showed that Sanbaidang and Beimayang were in basic health, while Qiaobeidang was in sub- health. The indicator system and assessment method are suitable for the rivers in eastern plains of China.[ Conclusion] The research could provide scientific references for the development, protection and restoration of lakes.

不同培育方式对橡胶树实生苗生理指标、养分及长势的影响

橡胶树(Hevea brasiliensis)种子催芽生长一般使用沙床培育,沙子是不可再生资源,为了选择一种适合橡胶树种子培育方式来替代对沙子的依赖,该研究通过水培、悬空培育和传统的沙培比较橡胶树实生苗第1蓬叶稳定时,苗木的生长势、生理指标及养分含量。结果表明,水培实生苗地上部株高、茎粗、叶面积的长势最佳,壮苗指数和生物量的含量最高,但其根太长,根相对较细。水培的叶、茎、根的可溶性糖、丙二醛、游离脯氨酸、超氧化物歧化酶的含量均较低;水培和悬空培育的叶片和茎的叶绿素、类胡萝卜素及根系活力的含量没有显著性差异,均高于沙培。水培的叶、茎、根中的氮和磷含量最低,沙培的最高;而水培实生苗根和茎中钾的含量较高,叶片中含量与悬空培育、沙培均没有显著性差异;悬空培育在叶、茎、根中钾的含量最低。水培促进了苗木的生长,降低干旱胁迫,提高养分利用率,但后续还需调控根系,建设良好根团。悬空培育的苗木长势较弱,还需进一步完善方法。

不同配比基质对草莓扦插苗生长的影响

为筛选适合培育草莓扦插苗的基质配方,本研究以草莓品种天使8号为试验材料,通过测定不同配比基质的理化指标及草莓扦插苗的生长指标,分析不同基质对草莓扦插苗生长的影响。结果表明,不同配比基质的总孔隙度、持水孔隙度、通气孔隙度存在差异,并且不同配比基质对草莓扦插苗生长的影响不同。其中椰糠∶草炭∶珍珠岩=4∶1∶1(重量比)为最佳基质配比,该配比基质的容重、总孔隙度、持水孔隙度较高。使用该基质培育的草莓扦插苗的叶柄粗、株高、茎粗、叶柄长、叶长和叶宽较大,地下部鲜重和地下部干重较大,同时草莓扦插苗气孔导度、胞间CO 2浓度、蒸腾速率较高。本研究结果为草莓穴盘扦插育苗的基质配置提供了参考。

不同供磷水平对椰枣幼苗生长、生理指标和营养元素含量的影响

【目的】通过分析不同供磷水平对椰枣幼苗生长、生理指标和营养元素含量的影响,为构建椰枣幼苗平衡施肥技术提供理论依据。【方法】以椰枣幼苗为试验材料,采用盆栽试验,设4个供磷水平处理,浓度分别为5(CK)、100、1000和5000μmol/L,培养7个月后,观察测定幼苗的生长、生理指标和营养元素含量。【结果】5μmol/L供磷水平下,椰枣幼苗长势弱;100μmol/L供磷水平下椰枣幼苗的根部鲜重显著低于1000μmol/L供磷水平(P<0.05,下同);1000μmol/L供磷水平下椰枣幼苗长势好,其根部鲜重、地上部干重、株高增加量、植株磷含量、植株磷累积量、第3叶和第6叶片中的可溶性蛋白含量均显著大于CK;5000μmol/L供磷水平下,新抽叶片密集,根部磷利用效率和植株磷利用效率最低。同一供磷水平下,椰枣幼苗茎尖中的磷含量高于叶片和根尖。不同供磷水平对地上部和根部氮、钾、钙、镁、钠、铝元素的含量影响不同。随着供磷水平的增加,地上部和根部的钾、铝含量,以及地上部钙含量均先增加后降低,地上部镁含量逐渐增加,根部钙、镁含量逐渐降低;5000μmol/L供磷水平下,地上部和根部的钠含量达最高。1000μmol/L供磷水平下,椰枣幼苗地上部的氮、钾、镁、钠、铝的累积量,地上部氮利用效率,以及地上部和根部的钙利用效率显著大于CK。【结论】营养液中的供磷水平会影响椰枣幼苗的长势、生理指标及营养元素的含量、累积量和利用效率。过低或者过高供磷水平均不利于椰枣幼苗的生长,1000μmol/L供磷水平下,椰枣幼苗长势良好。

轻基质配比对蚬木容器苗生长的影响

[目的]筛选适宜蚬木容器苗生长的育苗基质配方,为其容器苗的培育提供依据。[方法]以椰糠、泥炭土、珍珠岩和蛭石为原料,按照9∶1∶0∶0、8∶2∶0∶0、7∶3∶0∶0、8∶1∶0.5∶0.5、7∶1∶1∶1、6∶1∶1.5∶1.5的体积比配制基质(L_(1)~L_(6)),分别以椰糠(CK_(1))、黄心土(CK_(2))和椰糠+3.0 kg·m^(-3)缓释肥(CK 3)为对照。采用单因素随机区组设计,比较不同配比基质的理化性质;测定不同配比基质处理下蚬木容器苗的生长指标、叶面积和SPAD值,并进行相关性分析与隶属函数值计算。[结果](1)L_(1)~L_(6)处理基质的干容重为0.128~0.192 g·cm^(-3),总孔隙度为81.207%~86.497%,pH值为6.530~6.995,全氮、全磷和全钾含量分别介于1.135~4.830、0.121~0.274和4.512~6.709 g·kg^(-1)之间,均适合蚬木生长。(2)2021年3月L_(1)~L_(6)处理平均苗高为28.58~32.29 cm,平均地径为5.02~5.32 mm,各处理苗木的生长总体上优于CK_(1)和CK_(2)。(3)相关性分析表明,苗木地下部分鲜物质量、地下部分干物质量、一级侧根数与基质干容重、湿容重呈极显著负相关,与总孔隙度、非毛管孔隙度、pH值呈极显著或显著正相关,一级侧根数与全磷含量呈显著正相关。(4)隶属函数值综合评价结果表明,不同配比基质处理下苗木质量平均得分依次为:L_(6)>L_(2)>CK 3>L_(1)>CK_(1)>L_(3)>L_(4)>L_(5)>CK_(2)。[结论]比较隶属函数值评分结果,并综合不同基质的理化性质及其对苗木生长的影响,选择椰糠∶泥炭土∶珍珠岩∶蛭石为6∶1∶1.5∶1.5和8∶2∶0∶0的配比基质(L_(6)和L_(2)处理)作为蚬木容器苗的最适宜基质。

亚精胺+赤霉素在低温下对化橘红种子萌发及幼苗生理指标的影响

以化橘红种子为材料,在低温下,研究亚精胺(Spd)+赤霉素(GA3)对化橘红种子萌发、幼苗根系的生长、根活力及生理指标的影响,以培育壮苗。设置亚精胺浓度为0(CK)、0.10、0.15、0.20、0.25 mmol/L,分别添加80 mg/L的GA3溶液浸种、培养,测定种子发芽率、发芽势,幼苗根长、苗长、根重、苗重、根长/苗长、根重/苗重、抗氧化酶活性、渗透调节物质及膜质过氧化物含量的变化。结果表明:在低温条件下,亚精胺+赤霉素对化橘红种子的萌发有协同促进作用,发芽率、发芽势和发芽指数明显提高;单一使用赤霉素时,幼苗根的生长受到抑制,添加亚精胺后能明显缓解,缓解程度与Spd的浓度呈正相关。0.20 mmol/L亚精胺+80 mg/L赤霉素处理的根长、根重、根长/苗长、根重/苗重和根活力最高,其幼苗根系的抗氧化酶(SOD、POD、CAT)活性显著增强,渗透调节物质脯氨酸和可溶性蛋白的含量有所提高,丙二醛(MDA)含量降低。亚精胺+赤霉素复配能促进化橘红种子萌发、根系的生长和根活力的提高;能缓解低温对化橘红幼苗根的损害,提高种苗的抗寒性。

光质和光强变化对油松幼苗生长及非结构性碳水化合物的影响

为研究不同光质和光强对油松幼苗生长的影响,以培育5个月的油松容器苗为材料,设置红蓝绿混合光源(red∶blue∶green=6.5∶1.2∶2.3)、红蓝混光光源(red∶blue=5∶1)和全光谱植物生长灯作对照处理,分别在RGB和RB光源条件下50 cm处设置光子通量为90、150、210μmol·m^(-2)·s^(-1)的3个不同光照强度对油松幼苗继续补光4个月,揭示不同光质和光强对油松幼苗生长及非结构性碳水化合物的影响规律。结果表明:1)RB和RGB光质处理下除W1处理外,油松幼苗苗高和地径均高于CK,达到油松1年生播种苗的一级苗木标准。RGB处理下光照强度为210μmol·m^(-2)·s^(-1)时油松幼苗的苗高与地径最大,分别是CK处理的149.44%和152.00%。2)RB和RGB光质处理下整株干重、根冠比、根分配率及壮苗指数均在光照强度为210μmol·m^(-2)·s^(-1)时最高。3)RB光质处理下光照强度为150μmol·m^(-2)·s^(-1)时油松幼苗的淀粉含量变化明显,RGB光质处理下光照强度为210μmol·m^(-2)·s^(-1)时油松幼苗的可溶性糖含量最多,且可溶性糖与淀粉含量之间的转化相对稳定。4)RB和RGB光质处理下油松幼苗整株生物量、地径和苗高与淀粉含量存在正相关,与可溶性糖含量存在负相关(P<0.01)。

基于超分辨率重建与机器学习的油菜苗情监测方法

为优化养分管理和确保植株正常生长,以无人机遥感技术高效且非破坏采集田间作物苗情信息,监测油菜苗期的叶面积指数(LAI)与叶绿素相对含量(SPAD)。针对无人机因飞行高度与图像分辨率相互制约,监测效率与监测精度难以兼顾的问题,采用超分辨率重建方法,融合较低飞行高度拍摄高分辨率影像,重建较高飞行高度拍摄影像,建模完成后可通过拍摄飞行影像监测LAI和SPAD。试验设置3个氮肥梯度、3个播期、3个种植密度处理,在苗期利用无人机分别采集20m及40m 2个飞行高度的油菜苗影像,采用SRRestnet方法,对40m影像进行超分辨率重建。基于20m、40m及40m重建影像中提取的3种特征组合,利用偏最小二乘回归(PLSR)、随机森林(RF)、支持向量回归(SVR)3种机器学习方法对LAI和SPAD进行监测。结果表明,超分辨率重建后的图像在表型苗情监测中表现出良好效果,PLSR监测LAI、RF监测SPAD的监测精度最高,且40m重建图像的作业效率相比于20m图像提高48.6%。

施肥量对菩提树容器苗生长及养分累积的影响

探讨不同施肥量对菩提树容器苗生长和养分累积的影响,为北方地区菩提树容器育苗栽培措施提供理论参考依据。以1 a生菩提树扦插苗为试验材料,以美植袋为容器进行栽植,采用随机区组设计,设定对照和7个不同氮磷钾配比共8个处理(F_(1)~F_(8)),施肥5次,间隔为15 d,施肥同时测定菩提树的苗高、地径,最后一次施肥2周后测定菩提树生物量及养分含量。结果表明:不同施肥量对菩提树容器苗生长具有显著影响,不同N、P、K配比施肥中,F_(4)(氮肥、钾肥、磷肥用量为N 6.0 g·株^(-1)、P_(2)O_(5)1.5 g·株^(-1)和0.3 g·株^(-1))施肥量下,菩提树株高生长最快,增长率为380%。F_(1)(氮肥、钾肥、磷肥用量为N 0.0 g·株^(-1)、P_(2)O_(5)1.0 g·株^(-1)和K_(2)O 0.3 g·株^(-1))处理下,菩提树地径增长最快,总生物量最高。(2)不同施肥量下,菩提树全氮、全磷、全钾含量在根、茎、叶中分布呈显著差异。在施P1.5 g·株^(-1)处理下,随着施N量增加,全株含氮量呈增加趋势,在施P 1 g·株^(-1)处理下,随着施N量增加,全株含氮量呈递减趋势。随着N、P肥的增施,全株钾含量降低,增施N、P,菩提树对钾肥吸收降低。(3)叶片生长量与茎部氮含量、全株氮含量及根部磷含量呈极显著正相关,根部生物量与叶氮含量呈极显著正相关,与叶片磷含量、全株磷含量呈正相关;总生物量与叶片氮含量、全株磷含量呈正相关。钾肥在氮磷肥施用时,促进氮磷肥的均衡吸收,促进菩提树容器苗的生长。在本研究施肥配比范围内,N、P_(2)O_(5)、K_(2)O分别为6.0、1.5和0.3 g时菩提树株高生长最快,在N、P_(2)O_(5)、K_(2)O分别为0.0、1.0和0.3 g时,菩提树根系生长最好。

甘蔗脱毒原种苗田间繁育过程中氮、磷、钾营养元素的吸收及累积特征

探讨甘蔗脱毒原种苗不同生长时期氮、磷、钾营养元素的累积需求状况,为甘蔗脱毒原种苗田间繁育栽培过程中养分管理提供参考。试验分别在2020、2021年进行,调查中糖1号甘蔗脱毒原种苗全生育期生长情况,测定其生物量及其在各生育阶段根、茎、叶中氮、磷、钾各营养元素的含量,并分析氮、磷、钾的累积量、阶段吸收量、日吸收速率。结果表明:甘蔗脱毒原种苗从种苗假植到种茎最佳收获时需6~7个月可达15茎节,在7、8月至9月下旬(茎1期至茎2期)蔗茎生长速度最快,以茎4期(10月下旬至11月下旬)干物质量累积增加最快,此阶段为生物量累积的关键阶段。在甘蔗脱毒原种苗全生育期中各元素含量及累积量从高到低依次为钾>氮>磷,在根茎叶各器官中蔗叶、蔗茎始终为氮、磷、钾含量相对较高的器官,氮、磷、钾累积量在茎伸长生长1期前主要贮存于蔗叶中,而后以蔗茎为新的主要贮存器官。甘蔗对氮、磷、钾的吸收比例在苗期和分蘖期分别为24.84%、26.18%、27.74%,在茎1~3期(7月下旬至10月下旬)分别为55.54%、58.61%、52.30%,茎4、5期(10月下旬至12月下旬)分别为19.62%、15.20%、19.96%。因此,可根据各元素的阶段吸收量进行合理施肥,进而提高甘蔗脱毒健康种苗的品质和经济效益。试验明确了甘蔗脱毒原种苗生长过程中对氮、磷、钾的需求状况,可为今后甘蔗脱毒健康种苗田间规模化繁育生产的科学合理施肥提供依据,提高脱毒原种苗田间繁育效率和养分资源利用效率。

配方施肥对铁心杉幼苗生长和生理生化指标的影响

【目的】旨在寻找最适合铁心杉幼苗生长的肥料配比。【方法】采用“3414”试验设计方案,设置14组肥料配比,以每组50盆的1年生铁心杉实生苗为材料,探究不同肥料配比对幼苗生长和生理生化指标的影响。【结果】与不施肥相比,合理施肥的铁心杉幼苗叶片的叶绿素含量最高提高了42.01%,可溶性糖含量最高提高了11.64%,可溶性蛋白含量最高提高了13.81%,游离脯氨酸含量最高提高了211.25%;在N_(2)P_(2)K_(1)的肥料配方下,铁心杉幼苗的苗高、根直径、地上生物量、地下生物量、总生物量及苗木质量指数达到最大值,地径、根表面积和总根长也处于中上水平。【结论】N_(2)P_(2)K_(1)(每盆施1.0 g N、1.0 g P、0.5 g K)是铁心杉幼苗最佳的施肥配方。

不同浓度矮壮素、萘乙酸和烯效唑对大葱苗期生长的影响

为探究不同植物生长调节剂对大葱苗期徒长的控制效果,研究了矮壮素、萘乙酸和烯效唑3种植物生长调节剂对大葱苗期生长的影响。结果表明,喷施3种植物生长调节剂均能显著增加大葱幼苗的根系数量、茎粗、壮苗指数和根冠比;矮壮素和烯效唑处理显著降低株高,萘乙酸处理则增加株高;矮壮素和萘乙酸处理的叶绿素含量增加,干质量增加,而喷施不同浓度烯效唑的叶片和假茎干质量在处理后35 d时分别较对照降低7.56%~31.59%和27.95%~47.33%。综合考虑大葱幼苗的形态指标和干物质分配比例,500 mg·L^(-1)烯效唑处理对大葱幼苗控制徒长的效果最好,壮苗指数和根冠比分别较对照提高111.00%和91.30%。

不同浓度调环酸钙对大葱幼苗生长的影响

以东森寒葱2号为试验材料,通过测定大葱苗期喷施调环酸钙(200、400、600、800 mg·L^(-1))处理的形态指标、叶绿素和根系活力等指标,探究不同浓度调环酸钙对大葱种苗质量的影响。结果表明,调环酸钙能有效增加大葱幼苗的假茎粗、假茎长度和叶片叶绿素含量,提高根系活力、促进根系生长,且其适宜浓度为600 mg·L^(-1)。处理后21 d,与清水对照相比,600 mg·L^(-1)调环酸钙处理的假茎粗、假茎长和根系活力分别提高了22.0%、66.9%和65.7%;根系、假茎、叶片和全株干质量分别增加38.5%、48.4%、34.6%和37.9%。与200 mg·L^(-1)矮壮素处理相比,600 mg·L^(-1)调环酸钙处理的根冠比、壮苗指数和总叶绿素含量分别上升23.0%、37.0%和19.4%。综上,叶面喷施600 mg·L^(-1)的调环酸钙能有效提高大葱种苗质量。

烟苗壮苗指数构建与生长过程素质评估

为在设施大棚控制条件下构建快速、准确、直观、全面判断烟苗素质的壮苗科学评价体系以及在烟苗生长过程中的素质评估阈值,以成苗期(播种后60 d)的烟苗为材料,利用模糊综合评价法和熵权法构建综合评价指数,采用K-means聚类分析筛选出壮苗关键指标并随机组合成30个壮苗指数,通过壮苗指数与综合评价指数相关性分析筛选出最适宜壮苗指数,另以生长发育时期(播种后30~60 d)的烟苗为材料,获得烟苗达到最优壮苗水平的时期和关键指标阈值。结果表明:1)设施大棚内不同位置的三盘烟苗组间差异显著。2)综合评价指数范围为0.377~0.778,筛选出的壮苗指数为:全株鲜重×叶绿素总量×地上干重/株高(r=0.766)。3)烟苗素质分为3个等级,即最优壮苗级别(壮苗指数≥0.519)、壮苗级别(壮苗指数:0.356~0.519)、弱苗级别(壮苗指数≤0.356)。4)播种后50 d左右达到最优壮苗水平,株高6.96 cm左右,全株鲜重7.59 g左右,地上干重0.35 g左右,叶绿素总量1.36 mg·g^(-1)左右。研究结果为烟草壮苗科学评价和壮苗形成过程的烟苗素质评估提供了理论依据与科学方法。