Mutual Effects of Boron and Zinc on Peanut (Arachis hypogaea L.) Growth and Mineral Nutrition

The mutual effects of boron (B) and zinc (Zn) on growth, total chlorophyll (Chl), membrane permeability (MP), and nutrient content were investigated in peanut (Arachis hypogaea L.). The soil was treated with five levels of B (0, 4, 8, 16, 32 mg kg^?1) and three levels of Zn (0, 10, 20 mg kg^?1). Plant growth was progressively depressed with increasing of B. However, Zn addition had an inhibitory effect on B toxicity and decreased growth reduction caused by excess B. In Zn-untreated plants, B and Zn contents were enhanced by increasing of B; moreover, both Zn and B addition enhanced Zn content. The Chl content decreased and MP increased, resulting from B toxicity; however, Zn addition partially ameliorated the adverse effects of B toxicity on Chl and MP. Increasing B enhanced phosphorus (P), potassium (K), calcium (Ca), iron (Fe), Zn, copper (Cu), and sodium (Na) contents in peanut shoots.     

Changes in photosynthesis and antioxidant metabolism of cotton (Gossypium hirsutum L.) plants in response to manganese stress

ABSTRACT

This study aimed to assess the physiological and biochemical responses of cotton plants to manganese (Mn²⁺) nutrition. Four cotton genotypes (G1 – TMG 47; G2 – FM 975 WS; G3 – TMG 11 WS and G4 – IMA 8405 GLT) were grown in nutrient solution under two Mn²⁺ concentrations (2 and 200 µmol L^?1) for 10 days. No visible symptoms of Mn²⁺ toxicity were observed in the genotypes tested. All genotypes showed a marked increase in leaf chlorophylls, pheophytins, carotenoids, sucrose and total sugars concentration in response to high Mn²⁺ in a nutrient solution. However, the net photosynthetic rate, stomatal conductance, internal carbon dioxide concentration and transpiration decreased in genotypes G1 and G2 growing under 200 µmol L^?1. Antioxidant enzymes such as superoxide dismutase (SOD), ascorbate peroxidase (APX) and glutathione reductase (GR) activities increased in genotypes G1, G3 and G4. Cotton genotypes showed an increased leaf antioxidant and sugar metabolism as a possible strategy to mitigate oxidative stress. The decrease in the net photosynthetic rate and stomatal conductance; the increased antioxidant enzymes activities (SOD, APX and GR); and the increase in leaf sucrose and total sugar concentration were the main physiological and biochemical responses in cotton plants to Mn²⁺ stress.     

Agronomic traits at the seedling stage,yield, and fiber quality in two cotton (Gossypium hirsutum L.) cultivars in response to phosphorus deficiency

ABSTRACT

Cotton is critical for phosphorus demands and very sensitive for its deficiency. However, identifying the effect of low-phosphorus tolerance on cotton growth, yield, and fiber quality by reducing phosphorus consumption. This may help to develop phosphorus-tolerant high-yielding cotton cultivars. In a two-year repeated (2015 and 2016) hydroponic experiment (using 0.01 and 1 mM KH₂PO₄), two cotton cultivars with phosphorus sensitivity (Lu 54; a low-phosphorus sensitive and Yuzaomian 9110; a low-phosphorus tolerant) were screened on the base of agronomic traits and physiological indices through correlation analysis, cluster analysis and principal component analysis from 16 cotton cultivars. Low phosphorus nutrition reduced the plant height, leaf number, leaf area, phosphorus accumulation and biomass in various organs of seedlings. The deficiency negatively affected the morphogenesis of seedlings, as well as yield and fiber quality. Further, these screened cultivars were tested in a pot experiment with 0, 50, 100, 150, 200 kg P₂O₅ ha^?1 during 2016 and 2017. It was found to have a significant (P< 0.05) difference in boll number, lint yield, fiber strength, and micronaire at the harvest. Furthermore, after collectively analyzed the characteristics of Lu 54 and Yuzaomian 9110, there were six key indices that could improve the low phosphorus tolerance of cotton cultivars. These were root phosphorus accumulation, stem phosphorus accumulation percentage, leaf and total biomass of seedlings, seed cotton weight per boll and fiber length.     

膜下高频滴灌对土壤温湿环境及棉花产量的影响

以田间试验为基础,对高频覆膜滴灌条件下土壤水分、温度以及棉花的耗水过程和生长状况进行了观测。结果表明,高频滴灌条件下,灌水次数及灌水量分别比对照多20次和596.2mm,土壤含水率水平较高,棉花根系吸水阻力小,耗水强度大,可达7.4mm/d。各生育阶段高频滴灌的土壤温度比对照低,而且根系分布浅。另外,高频滴灌棉花地上营养器官生长旺盛,叶面积指数很大,可达到6.6。然而,高频滴灌棉花产量比对照低111.34kg/hm2,水分利用效率低。试验认为高频滴灌的生产意义不显著。     

Boron Fertilization in Sunflower (Helianthus annuus L.) in an Inceptisol of West Bengal,India

This study is a synthesis of information on growth, yield, and boron-use efficiency of hybrid sunflower (cultivar Aditya) in an inceptisol (Gangetic alluvium) of West Bengal, India, under varied proportions of soil and foliar-applied boron. Foliar spray of boron (B), under all circumstances, performed better than soil application of B fertilizers with regard to sunflower seed and total dry-matter yield, B uptake, and B-use efficiencies, while 0.2 percent foliar B spray was associated with greatest B recoveries, B-use efficiencies, and sunflower seed yields in the experimental years.     

施氮量对不同开花期棉（Gossypium hirsutum L.）铃纤维细度和成熟度形成的影响

为兼顾试验的重复性和生态区域性,选用高品质棉（科棉1号）和常规棉（美棉33B）品种为材料,于2005年分别在江苏南京（118o50E, 32o02N,长江流域下游棉区）和江苏徐州（11711E, 3415N,黄河流域黄淮棉区）设置施氮量（低氮:N 0 kg/hm2;适氮:N 240 kg/hm2;高氮:N 480 kg/hm2）试验,研究施氮量对不同开花期棉铃纤维细度、成熟度和马克隆值形成的影响。结果表明:（1）施氮量显著影响棉纤维细度、成熟度和马克隆值的形成过程,但三者在不同开花期对氮素水平的响应不同,施氮量与开花期对棉纤维细度、成熟度和马克隆值的形成存在互作效应。8月10日前开花的棉铃,铃期［花后0～50 d （DPA）］日均温在23.3 oC以上,纤维细度、马克隆值以N 0 kg/hm2施氮量下最大,棉纤维马克隆值与纤维细度的相关性较大;8月25日开花的棉铃（铃期日均温在20.8～23.3 oC之间）,纤维成熟度、马克隆值以N 240 kg/hm2施氮量下最大;9月10日开花棉铃（铃期日均温低于20.8 oC）,纤维细度、成熟度和马克隆值均以N 480 kg/hm2最大,棉纤维马克隆值与纤维成熟度的相关性增强。（2）影响不同开花期间纤维细度、成熟度和马克隆值的主要因素是铃期日均温,最终纤维细度、成熟度和马克隆值在不同施氮量之间的变异与不同开花期（铃期日均温不同）间的变异比较,前者显著小于后者。综上,因开花期不同而形成的铃期日均温是决定细度、成熟度和马克隆值的最重要因素,施氮量可通过对位叶叶氮浓度NA影响棉纤维细度、成熟度和马克隆值的形成过程,增加施氮量可减小上述指标在不同开花期间的差异。     

Influence of Levels and Methods of Boron Application on the Yield and Uptake of Boron by Cotton in a Calcareous Soil of Punjab

A field experiment was conducted to study the influence of boron (B) application on yield and B uptake of cotton (Gossypium hirsutum L.) in B-deficient calcareous soil of south-west Punjab. The treatments comprise six levels of soil-applied B (0.0, 0.5, 1.0, 1.5, 2.0, and 2.5 mg B kg^?1soil) and two levels of foliar-applied B (0.1% and 0.2% borax and granubor solution) along with the common control (no B application). The experiment was laid out in RBD factorial design with three replications. The seed cotton yield and its attributing characters (plant height, number of sympodial and monopodial branches, boll weight, and number of boll per plant) and root biomass increased significantly with increasing levels of boron up to 1.0 mg B kg^?1 level over the control and then remained nonsignificant with further higher levels of soil-applied boron. Among foliar-applied boron levels, 0.1% borax solution was better than 0.2% borax solution. Soil-applied boron was at par with foliar-applied boron. The efficiency of borax and granubor was found to be equal in both sources of boron. The mean B content and its uptake by seed cotton and roots increased significantly up to 1.0 mg B kg^?1 soil-applied B level and then recorded nonsignificant with further higher levels of boron. For the foliar method of B application, the mean B content and its uptake by seed cotton increased significantly over the control. The mean available B content in soils (0–15 cm) at 45, 75, 105, and 145 days after sowing increased significantly over the control for all soil-applied B levels, while it remained nonsignificant over the control for all growth stages of cotton in foliar method of B application. Further, it was positively correlated with root biomass (r = 0.91), boron uptake by root (r = 0.98), and sympodial branch per plant (r = 0.81). The interaction of B application levels and sources was not significant for all studied traits. Regardless of B sources, B application had a significant effect on yield, yield attributes, and B uptake up to 1.0 mg B kg^?1 level for soil-applied B and 0.1% borax or granubor solution for foliar-applied B.     

膜下滴灌条件下棉株温湿度微环境

通过对膜下滴灌棉花根区土壤温度、水分、冠层叶温、气温及冠层空气湿度的观测,分析了该灌水条件下棉花土壤水、热关系,冠层温、湿度关系,结果发现:棉花根区土壤水分与温度之比在深度方向上近似呈线性关系,冠层叶—气温差与空气饱和差也呈线性关系,说明膜下滴灌技术能够为棉花根系提供良好的吸水环境,有利于棉花生长。     

N+离子注入陆地棉花粉对胚珠DNA及M1代cDNA表达的影响

通过对胚珠DNA的SSR标记分析,在DNA水平上检测氮离子束诱变后胚珠的多态性变化,结果表明,离子注入陆地棉花粉后再给雌蕊授粉,会对胚珠的DNA多态性产生影响,表明在一定程度上改变了花粉中精细胞的DNA序列;利用抑制性消减杂交(SSH)分离N+离子诱变花粉和对照正常花粉分别给雌蕊授粉后产生的M1代植株叶片间表达有差异的cDNA片段,建立差异表达cDNA文库。已测序的有50个缩减cDNA克隆,根据BLAST网络服务检索查询EMBLGen、 Bank、DDBJ和PDB的核苷酸序列数据库以及蛋白质氨基酸序列数据库,进行序列联配,结果发现52%序列在数据库中都有同源的棉属来源的EST。38个EST与其他物种已知基因部分区域的同源性为56%-100%,占总EST的76%;5条EST序列能在数据库中检索到同源性序列,但其功能（占10%）尚不清楚;9个EST能在数据库中发现为推测蛋白,占18%;4个EST在GenBank中没有查到对应的同源序列,占8%。     

黄土半干旱区元宝枫叶片气体交换参数对土壤水分的响应

在黄土高原半干旱地区，采用Li-6400便携式光合测定仪和TDR水分仪，对不同土壤水分处理下的元宝枫（Acer truncatum）盆栽苗木生长的生理生态特征进行观测。研究了叶片的净光合速率（Pn）、蒸腾速率（Tr）、水分利用效率（WUE）、气孔导度（Gs）、胞间CO2浓度（Ci）和气孔限制值（Ls）对土壤含水量（SWC）的响应过程，并探讨了在不同土壤水分胁迫程度下影响元宝枫叶片光合作用变化的规律，最后确定了元宝枫树种在黄土区适宜生长的土壤水分调控标准。结果表明：元宝枫叶片净光合速率最高时的SWC为14％，蒸腾速率最高时的SWC为15％，叶片水分利用效率最高时的SWC为13％，8％的SWC是严重水分胁迫下叶片光合速率降低由气孔因素限制到非气孔因素限制的转折点。根据半干旱地区林业建设以提高林木水分利用效率为核心的土壤水分管理思想，确定元宝枫树种在该区最适宜生长的SWC为11％～15％。     

Foliar Applied Phosphorous Enhanced Growth,Chlorophyll Contents,Gas Exchange Attributes and PUE in Wheat (Triticum aestivum L.)

A pot experiment was conducted to evaluate the foliar applied phosphorous with and without pre-plant dose (50 kg hac.^?1) of phosphorous on growth, chlorophyll contents, gas exchange parameters and phosphorous use efficiency (PUE) of wheat. The experiment was conducted in net house at Department of Crop Physiology, University of Agriculture Faisalabad, Pakistan. Two promising wheat cultivar AARI 2011 and FSD 2008 were used as a test crop with 5 foliar phosphorus (P) rates (0, 2, 4, 6, 8 kg ha^?1). The foliar applied P with pre-plant performed better than without pre-plant and control treatments. Foliar treatment of phosphorus at 6 kg ha^?1 P proved to be the best among other foliar treatments followed by 8 kg ha^?1 P. The foliar application of phosphorous at 6 kg hac.^?1 with pre-plant soil applied P increased the shoot length, root length, shoot fresh weight, root fresh weight, shoot dry weight and root dry weight. The chlorophyll contents (Chl. a and b) were increased with the foliar application of phosphorous. The gas exchange parameters (net carbon dioxide (CO₂) assimilation rate, transpiration rate, stomatal conductance and sub-stomatal CO₂ rate) were significantly improved by foliar applied P. The maximum values of net CO₂ assimilation rate (5.27 μ mol m^?2 sec.^?1), transpiration rate (3.44 μ mol m^?2 sec.^?1), stomatal conductance (0.81 μ mol m^?2 sec.^?1) and sub-stomatal CO₂ (271.67 μ mol m^?2 sec.^?1), were recorded in the treatment where P was foliar applied at 6 kg hac.^?1 with pre-plant soil applied Phosphorous. The foliar application of phosphorous with pre-plant soil applied P enhanced Phosphorous use efficiency (PUE) in both varieties. The maximum value of PUE (15.42%) was recorded in the treatment where foliar feeding of P was done at 6 kg hac.^?1 with pre-plant soil applied P in both genotypes.     

白榆沙棘光合生理参数与土壤含水量关系研究

采用Li-6400便携式光合仪在模拟光照条件下，对不同水分处理的白榆、沙棘进行观测。观测参数包括：净光合速率、气孔导度、蒸腾速率、胞间CO2浓度等。并且运用SPSS数据处理软件进行分析，从而确定白榆、沙棘光合生理参数与土壤含水量之间的关系，并在研究过程中对试验地土壤水分进行有效性评价；其等级分别为：无产无效水、低产低效水、高产高效水、高产低效水。而把高产高效水作为指导当地林业生产的土壤水分管理条件。结果表明白榆沙棘具有高产高效的土壤含水量分别为11．4％～17．2％；9．5％～16．5％。     

土壤水分对山杏光合作用日变化过程的影响

在半干旱黄土丘陵区,应用CIRAS -2型光合作用测定系统,通过测定8个土壤水分梯度下山杏(Prunus sibirica L.)叶片光合生理参数的日变化过程,探讨土壤水分变化对山杏光合作用日变化过程的影响.结果表明:1)山杏光合作用日变化过程和光合午休的原因,随土壤水分的变化而明显不同,当土壤相对含水量(WT)在56.1％～66.1％之同时,山杏没有发生光合作用午休现象,但超出此土壤水分范围会发生不同程度的光合午休现象,当Wr在93.2％ ～77.0％之间时,山杏光合午休的主要原因是气孔因素限制,当Wr在49.3％ ～37.3％之间时,光合午休的主要原因开始由气孔因素向非气孔因素转变,当Wr小于37.3％后,光合午休的主要原因为非气孔因素限制,即叶肉细胞光合能力下降;2)当Wr在49.3％～77.0％之间时,山杏同时具有较高的光合速率和水分利用效率.     

Plant analysis diagnostic indices for boron nutrition of mungbean (Vigna radiata L.) cultivars grown in a rainfed calcareous soil

Boron requirement of mungbean was assessed from yield response curves based on field experiment during 2010-11. Four cultivars, i.e., NM-11, NM-2006, Chakwal Mung-2006 and AZRI Mung-2006 were grown in a boron (B)-deficient calcareous soil by applying B at 0, 0.5, 1.0, 2.0, and 4.0 kg ha^?I. Boron application significantly increased grain yield and B uptake by all the mungbean cultivars over control. Maximum grain yield increases were: cv. NM-11, 20%; cv. NM-2006, 24%; cv. Chakwal Mung-2006, 26%; and cv. AZRI Mung-2006, 28%. The cultivars varied in B efficiency and cv. NM-11 was most B efficient (83%) while cv. AZRI Mung-2006 was the least B efficient (78%). Fertilizer B requirement (kg ha^?1) for 95% of the maximum grain yield was: 0.60 for cv. AZRI Mung-2006, 0.70 for cv. Chakwal Mung-2006, 0.75 for cv. NM-2006, and 0.85 for cv. NM-11. Plant tissue critical B concentration in leaves was higher than in seeds.     

Remobilization efficiency and photosynthetic characteristics of five barley (Hordeum vulgare L.) cultivars under terminal drought stress

Drought is an important limiting factor which can cause major loss in barley productivity. A field experiment was conducted to investigate the effects of irrigation regimes on assimilate remobilization and photosynthetic characteristics of five barley cultivars in 2012 and 2013. There were four levels of irrigation including well-watered [soil moisture content in root depth kept at 100% field capacity (FC)], mild drought (75% FC), severe drought (50% FC), and very severe drought (25% FC). Results showed that Karoon and Valfajr cultivars had the maximum net photosynthetic rate (P_n) ranged from 16.3 to 19.3 µmol CO₂ m^?2 s^?1 under very severe drought. Stomatal conductance (gs) was affected by drought so that Karoon and Valfajr had the lowest gs under severe and very severe drought. By improving the drought, remobilization efficiency in Karoon and Valfajr increased from 18.3% in well-watered to 54.1% under severe drought. In both years under severe and very severe drought, maximum 1000-grain weight and grain yield was obtained in Valfajr and Karoon. Overall, in arid areas, applying suitable irrigation regimes such as mild or severe drought can control soil drying, so that suitable cultivars such as Karoon and Valfajr can rehydrate overnight, and yield might not be inhibited severely.     

不同土壤水分对幼龄梨树生理特性及生物量的影响

以山西省吉县地区幼龄梨树为研究对象,在盆栽试验的基础上,研究了不同土壤水分条件对幼龄梨树生长相关生理指标的影响。结果表明,幼龄梨树的蒸腾速率日变化趋势在SWC≤10%时,呈现双峰曲线,第一峰值出现在上午10时,第二个高峰出现在14时左右。SWC>10%时,蒸腾速率日变化为单峰曲线,在中午12时达到一天中的最大值;不同土壤水分条件下,幼龄梨树净光合速率日变化呈“S”形,在上午8时左右达到最大峰值,在12时左右出现“光午休”低谷,土壤水分缺失明显降低净光合速率。发挥较大水分利用效率的土壤含水量范围为10%～14%。单株幼龄梨树的生物量分布总体为干>根>叶>枝,土壤水分较为充足时幼龄梨树积累的干物质的分配有偏向于叶和枝的趋势;而在干旱的情况下幼龄梨树干物质分配有偏向于根和干的趋势。     

3种阔叶树气体交换特性及水分利用效率影响因子的研究

通过测定刺楸、黄连木、栾树旱季和雨季气体交换参数及其周围环境因子的日变化,分析水分生理生态特性,探讨各生理生态因子对水分利用效率的影响。结果表明：光合有效辐射与温度均呈单峰型,空气相对湿度呈“U”型。蒸腾速率日变化3个树种在旱季和雨季均呈单峰型。净光合速率日变化刺楸在旱季为双峰型,在雨季为单峰型,而黄连木、栾树在旱季和雨季均为单峰型。水分利用效率日变化在雨季3个树种呈单峰型,在旱季黄连木呈单峰型,而刺楸和栾树呈双峰型。逐步回归分析发现,影响3个树种水分利用效率的因子主要有胞间CO2浓度(极显著负相关)、大气CO2浓度(极显著正相关)、空气相对湿度(正相关)和叶温(负相关)等。通过主成分分析,可将影响刺楸、栾树水分利用效率的因子归纳为3类,即温度、气孔导度和CO2浓度;黄连木可归纳为两类,即温度和气孔导度。     

果树蒸腾光合及水分利用率与土壤含水量关系研究

以山西省吉县地区幼龄苹果、梨为研究对象,在盆栽实验的基础上,研究了不同土壤含水量条件下两种果树蒸腾速率、光合速率日变化规律,得出苹果、梨的蒸腾速率在土壤含水量6%～10%时呈现双峰曲线,中午出现低谷区;而在土壤含水量12%～20%时,呈现正午峰值型的单峰曲线。在此基础上研究了蒸腾、光合及水分利用率与土壤含水量的关系：蒸腾速率、水分利用率与土壤含水量相关关系可用三次四项式描述,而光合速率与土壤含水量呈二次相关关系。黄土高原半干旱区适宜苹果生长的土壤水分范围为12%～14%,最佳土壤含水量为12.37%;适宜梨树生长的土壤水分范围为12%～16%,最佳土壤含水量为15.19%。     

半固定与固定沙地油蒿枝条水势及气体交换特征

为揭示半固定沙地和固定沙地油蒿生长差异的原因,测定了毛乌素沙地自然生长在半固定与固定沙地油蒿的气体交换参数、枝条水势及土壤含水量,分析了油蒿气体交换参数、枝条水势日变化特征及土壤水分对其的影响。结果表明:半固定沙地与固定沙地油蒿枝条水势与气体交换参数日变化趋势相同,半固定沙地油蒿日均净净净光合速率是固定沙地的1.3倍,蒸腾速率是固定沙地的1.23倍,其枝条水势也高于固定沙地,两种立地条件下油蒿枝条水势和气体交换参数的不同主要是由于沙地中土壤水分含量不同所引起。     

红壤地区直播油菜施硼对籽粒产量和品质的影响

红壤地区是我国重要的油菜种植区,研究直播冬油菜硼肥施用效果,为直播油菜科学施硼提供理论依据,对促进区域油菜产业发展有重要意义。2017—2018年在江西、湖南、湖北南部和广西北部油菜主产区布置7个硼肥大田试验,设置不施硼、施硼肥(含硼量100 g·kg~(–1))4.5 kg·hm~(–2)、9.0 kg·hm~(–2)、13.5 kg·hm~(–2)四个处理。结果表明,红壤地区土壤有效硼普遍含量低,直播油菜施硼增产效果显著,油菜籽平均产量和施硼经济效益在硼肥用量9.0kg·hm~(–2)时最高,与不施硼相比增产1 021 kg·hm~(–2),增产率达110.6%,分别较施用硼肥4.5 kg·hm~(–2)和13.5 kg·hm~(–2)增产16.6%和3.1%。施硼显著增加直播油菜收获密度、单株角果数和每角粒数,进而增加了油菜产量;同时硼肥的施用可显著提高油菜籽的含油率、油酸和亚油酸含量,与不施硼相比,施用硼肥9.0 kg·hm~(–2)处理各品质指标分别增加26.9%、45.9%和72.6%,相应增加产油量136.1%。在硼肥用量13.5 kg·hm~(–2)范围内,油菜地上部硼含量和硼累积量随着施硼量的增加而增加,但硼肥利用率呈现降低的趋势,硼肥用量为9.0 kg·hm~(–2)处理的硼肥当季利用率也仅为9.4%。综合结果显示,红壤地区直播油菜施硼增产增收效果显著,直播油菜生产中应重视硼肥的合理施用,区域硼肥的推荐用量为9.0 kg·hm~(–2)左右。