VARIATION AND INTERRELATIONS AMONG NUTRIENT ELEMENTS IN WHEAT LEAVES USED FOR FORAGE

Dual purpose wheat provides valuable forage resources for cattle in the southern Great Plains during winter. In this study, 96 recombinant inbred lines (RILs) were analyzed for variation in concentrations of 11 mineral elements in leaves. The mean concentration was 133.4 mg kg^?1 for manganese (Mn) and 293 mg kg^?1 for iron (Fe), being much higher than the 30 mg kg ^?1 recommended for each of these two minor mineral elements. Mean concentrations of zinc (Zn) (24.1 mg kg^?1) and copper (Cu) (4.4 mg kg^?1) were much lower than recommended concentrations. A highly significant correlation was detected between major minerals, magnesium (Mg) and calcium (Ca) (r = 0.9272**) and between minor minerals, Fe and nickel (Ni) (r = 0.8905**). Copper had no significant correlation with any minerals except Zn (r = 0.2529*), whereas Zn had significant correlations with all of the tested minerals except Cu, Mn, and Ni. The interrelations between different minerals provided information for effective selection strategy for ideal mineral concentrations in breeding of dual purpose wheat.     

THE EFFECTS OF LIGHT REGIME AND SUBSTRATE ON FLOWER PRODUCTIVITY AND LEAF MINERAL COMPOSITION IN TWO GERBERA CULTIVARS

This research evaluates the influence of light regime and substrate composition on the flower productivity and leaf macronutrient content of two gerbera cultivars (‘Ruby Red’ and ‘Vino’) grown in a greenhouse. A special emphasis was given to macro-element ratios in gerbera leaf. The results confirm positive influence of supplemental lighting on flower yield in both gerbera cultivars. Also, mixed substrate (coco fiber + rice husks) resulted with higher flower yield. Cultivar ‘Vino’ showed better productivity and significantly lower concentration of nitrogen (N), potassium (K), and magnesium (Mg) as compared to ‘Ruby Red’. The total flower productivity per plant correlated with some of the tested macronutrients in gerbera leaf (N, K, Mg) only in natural light conditions. Among all calculated leaf nutrient ratios, only P/Mg was significantly and positively correlated to flower yield, based on data from both light variants.     

YIELD AND MINERAL CONCENTRATIONS OF SOUTHEASTERN UNITED STATES OAT CULTIVARS USED FOR FORAGE

A shift in oat (Avena sativa L.) production from grain to forage (hay and grazing) is occurring in the southeastern USA. However, most available cultivars were developed for improved grain production, rather than forage yield. We field tested several standard and new oat releases over 2 years, using repeated clippings to determine forage yield, nutrient uptake, and the potential to match plant nutrients with cattle mineral dietary needs. There were no differences in total annual forage yield among the tested cultivars within years but there was a difference between years. Forage tissue phosphorus (P), magnesium (Mg), and calcium (Ca) were sufficient, potassium (K), sulfur (S), and manganese (Mn) were excessive, and iron (Fe), copper (Cu), and zinc (Zn) were occasionally or frequently deficient to meet daily cattle dietary mineral needs. Sulfur, Cu, Fe, Zn, and Mn may be the most challenging to regulate in U.S. Coastal Plain soils at concentrations that satisfy both, oat and cattle nutritional requirements.     

VARIATION IN PHOSPHORUS EFFICIENCY AMONG BRASSICA CULTIVARS I: INTERNAL UTILIZATION AND PHOSPHORUS REMOBILIZATION

Plants have adapted a number of mechanisms to cope with widespread phosphorus (P) deficiency in arable lands. Crop species and even cultivars differ widely in one or more of these adaptive mechanisms hence, in P efficiency. Identification of these mechanisms is pre-requisite for long term breeding programs. Two independent experiments were conducted to study the possible mechanisms of P efficiency in Brassica cultivars. Eight Brassica cultivars (‘B.S.A.’, ‘Toria’, ‘Toria Selection’, ‘Brown Raya’, ‘Peela Raya’, ‘Dunkeld’, ‘Rainbow’, and ‘CON-1’) were selected on the basis of differences in growth under P deficiency from preliminary experiment. In the first experiment, cultivars were grown for 40 days in sand supplied either with sparingly soluble phosphate rock (PR) or soluble mono-ammonium phosphate (MAP). Cultivars differed significantly (P<0.05) for biomass production, P contents and P use efficiency. Low P availability in PR treatment resulted in significantly lower dry weights and P contents than those grown with MAP. The cultivars ‘Rainbow’, ‘Brown Raya’ and ‘Dunkeld’ accumulated more biomass (3.2 g/pot) and P contents (3.0 mg/pot) than other cultivars when grown with PR. Root dry weight was significantly correlated with shoot dry weight, shoot P content and total P content (r > 0.65) indicating significance of improved root growth for P acquisition. While in the second experiment cultivars were grown with adequate P for 30 days and then P was withdrawn from the nutrient solution by replacing fresh P free nutrient solution for 10 days. Induced P deficiency increased P contents in young leaves by two folds indicating remobilization of P from older leaves and shoot. Nonetheless cultivars varied for remobilization but differences in P remobilization could not explain the differences in P utilization efficiency among cultivars. Hence further experimentation to study root morphology, P uptake, and organic acid exudation by these cultivars in relation to P deficiency is recommended.     

VARIATION IN PHOSPHORUS EFFICIENCY AMONG BRASSICA CULTIVARS II: CHANGES IN ROOT MORPHOLOGY AND CARBOXYLATE EXUDATION

Increased phosphorus (P) efficiency is needed to sustain agriculture productivity on soils with low available P. Significant differences were found among Brassica cultivars for growth, P utilization, and remobilization under P deficiency (see our companion paper, Aziz et al., 2011a). To identify the possible mechanisms of P acquisition from low soluble P compounds, four cultivars (‘Rainbow’, ‘CON-1’, ‘Dunkeld’, and ‘Peela Raya’) were selected to ascertain the relationship of their differential P acquisition and growth with their root length in soil and with organic acid release pattern in solution culture experiments. For this purpose their growth and P acquisition from phosphate rock (PR) was compared with calcium di-hydrogen phosphate (Ca-P) when adding uniform dose of 100 mg P kg^?1 soil separately from the two sources. Biomass accumulation, root length, root fineness, plant P uptake and ash alkalinity was significantly (P < 0.01) different in plants of all the four cultivars when supplied with PR or Ca-P in soil. Minimum biomass produced by ‘Peela Raya’ grown with either P source was followed by ‘CON-1’, ‘Dunkeld’, and ‘Rainbow’ in ascending order. Shoot dry matter production had a significant positive correlation with root dry matter production (r = 0.85, P < 0.01), root length (r = 0.59, P < 0.05) and root P uptake (r = 0.95, P < 0.01). Cultivars varied significantly for organic acid secretion in solution culture experiment. Higher quantities of secreted citric acid, malic acid and tartaric acid in solution culture experiment were measured for ‘Rainbow’ and ‘Dunkeld’ cultivars. Efficient performance of these two cultivars for growth and P uptake was associated with their longer roots and more secretion of organic acids especially citric acid.     

大棚设施土壤养分和重金属状况研究

对山东寿光不同棚龄大棚土壤速效N、P、K及重金属Cu、Zn、Cd、Pb含量调查表明:随大棚棚龄的增加,速效N、P含量有显著的增加,其增加量与棚龄呈极显著正相关,速效K含量增加幅度不大,即N、P、K施用不均衡;重金属Cu、Zn、Pb含量随大棚棚龄的增加有一定的增加,Cd含量没有明显的规律性,但这几项重金属含量均比农田含量要高,表明在大棚高强度施肥及人为活动影响下,引入了重金属;农田及大棚重金属含量均较土壤背景值有一定程度的增加,但未超出国家环境质量标准。     

植物体细胞无性系变异的研究与应用

本文综述了有关植物体细胞无性系变异的类型、机理、筛选与鉴定方法等方面的研究成果,并对其在新品种培育中的应用现状和前景进行了讨论。     

COMPARATIVE STUDIES ON THE IRON AND ZINC CONTENTS ESTIMATION USING ATOMIC ABSORPTION SPECTROPHOTOMETER AND GRAIN STAINING TECHNIQUES (PRUSSIAN BLUE AND DTZ) IN MAIZE GERMPLASMS

Malnutrition arising from dietary deficiency of critically important mineral micronutrients such as iron (Fe) and zinc (Zn) is a serious problem affecting nearly half of the world's population. Screening for micronutrients rich breeding lines includes the estimation of grain micronutrient contents in the seed samples using atomic absorption spectrophotometer (AAS). Though the protocol produces precise results, it is usually costly and time consuming. The nutritionist started searching for newer methods like staining the particular plant tissue with dyes so the initial screening of among vast germplasm lines becomes easier. A set of four hundred and thirty genotypes were used in this experiment wherein the reliability and the cost effectiveness of the use of the staining method in place of the estimation using AAS was investigated. The intensity of the color developed was directly proportional to the amount of iron and zinc in the grains and were scored as 1, 2, 3, 4, and 5. The genotype ‘UBC 7’ has got the maximum level of iron (65.43 mg kg^?1) with about 64 lines is found to contain higher levels of iron. The genotype ‘UMI 421’ had the maximum level of zinc (60.15 mg kg^?1) along with ten lines showing richer zinc levels. The genotypes namely ‘UMI 1069’, ‘UMI 630’, ‘UMI 473’, ‘UMI 327’, and ‘UMI 382’ are found to be having considerably higher levels of iron and zinc in the kernels. These lines may be used for the introgression of the traits concerning micronutrient enhancement into the popular elite cultivars. When compared to the estimation with AAS, the staining methods with Prussian Blue and Dithizone (DTZ: 1,5-diphenyl thiocarbazone) are found be very cost effective and precise in identifying and categorizing the lines as micronutrient rich/deficit. The varying color intensities serve as a reliable selection criterion for grain micronutrient contents in maize and other cereal crops. These protocols, could, therefore, be effectively used as the initial screening methodology and so the genotypes might be identified for higher grain micronutrient contents among huge population in a short period of time.     

NaCl处理对高、低芥酸油菜种子萌发和离体茎尖生长的影响

以2份高芥酸油菜绵油13号、高芥4号和2份低芥酸油菜绵恢PS-1-2、绵恢8号为试验供体材料,观察了组织培养条件下,NaCl胁迫对高、低芥酸油菜种子萌发和离体茎尖生长的影响。结果表明:经4g/L NaCl浸种和培养基中添加10g/L NaCl均对种子萌发率产生抑制作用,且高芥酸油菜种子的萌发率明显高于低芥酸油菜。比较2种方式浸种11d的萌发率,为4g/L NaCl浸种的低芥酸油菜材料高于无菌水浸种的材料,高芥酸油菜的表现则相反。培养基中添加6g/L NaCl对离体培养茎尖的存活率产生明显的抑制作用,高芥酸油菜茎尖生长的受抑制程度明显低于低芥酸油菜。可以得出结论,供试的高芥酸油菜在萌发和离体培养阶段的耐NaCl性明显优于低芥酸油菜。     

INVESTIGATIONS ON FOLIAR SPRAY OF BORON AND MANGANESE ON OIL CONTENT AND CONCENTRATIONS OF FATTY ACIDS IN SEEDS OF SUNFLOWER PLANT RAISED THROUGH SALINE WATER IRRIGATION

The objective of this experiment was to evaluate the effect of foliar fertilization of some micronutrients [i.e., manganese (Mn) and boron (B)] on reproductive yield and fatty acid concentrations of a standard sunflower hybrid (‘NuSun 636') irrigated with different concentrations of saline water made by dissolving sea salt. Reproductive yield showed a significant decrease with the increase in salt in the rooting medium. However, foliar sprays of boric acid (H₃BO₃) and manganese chloride (MnCl₂) showed a significant increase in seed number, seed weight, and oil content of seeds in the nonsaline control, which persisted even under saline water irrigation. An increase under the MnCl₂ spray was more than with H₃BO₃ irrespective of non saline or saline water irrigation. Increasing levels of salinity appeared to be responsible for a decrease in oleic monounsaturated fatty acid concentration and an increase in the linoleic polyunsaturated, palmitic and stearic saturated fatty acid content whereas no significant change was found in linolenic polyunsaturated fatty acid content. Foliar applications of H₃BO₃ and MnCl₂ brought some beneficial alteration in fatty acid concentrations of sunflower. Foliar application of H₃BO₃ caused a significant increase in palmitic and stearic saturated fatty acids and linoleic polyunsaturated fatty acids in control as well as under saline conditions. Oleic monounsaturated fatty acid concentration showed a decline under H₃BO₃ treatment irrespective to nonsaline or saline conditions. Foliar applications of MnCl₂ increased the concentration of palmitic saturated fatty acid and oleic monounsaturated fatty acid irrespective to the plant growth under non saline or saline conditions. While stearic saturated fatty acid, linoleic and linolenic polyunsaturated fatty acid decreased with the application of manganese as compared to the non sprayed control.     

十和田近等基因系糙米五种矿质元素含量变异及分布分析

测定了十和田×(十和田和丽粳2号BC4F5)BC5F6近等基因系糙米中Ca、P、K、Mg和S5种元素含量,并对5种元素进行了相关性、线性回归和聚类分析,旨在揭示群体中5种元素含量的分布规律。结果显示:(1)近等基因系群体中P元素含量变异系数最大(16.52%),K元素最小(11.20%),除S外其余元素含量都符合正态分布;(2)5种元素间为显著或极显著正相关,其中K与Mg元素相关性最大,Ca与S元素最小;(3)Ca与P、K元素,以及S与K元素间的相关性受其他元素影响较大;(4)除S与Ca外,其余元素都符合线性回归分布,相对而言群体中低S元素含量株系较多;(5)5种元素被聚成3类,K、Mg和P为一类(Ⅰ类),Ca为一类(Ⅱ类),S为一类(Ⅲ类),Ⅰ类和Ⅱ类关系较近,与Ⅲ类关系较远。     

A NEW STRATEGY TO ENRICH CALCIUM NUTRITION OF FRUIT: SYNERGISTIC EFFECTS OF POSTHARVEST FOLIAR CALCIUM AND BORON SPRAYS

The objective of the study is to investigate the role of calcium (Ca) and boron (B) synergy in higher maintenance of Ca in fruit buds during senescence. To study the hypothesis, an experiment was conducted for two years in two ‘Starking Delicious’ apple (Malus domastica Borkh.) orchards established on seedling rootstocks in Banaz, Usak, Turkey. Treatments composed of postharvest foliar sprays of Ca at rate of 15.13 kg h^?1, B at rate of 2.47 kg h^?1 and their combination (Ca+B) compared with control trees sprayed with water. Fruiting spurs, flower ovaries, young and mature fruits were sampled and analyzed for their Ca, B, potassium (K) and magnesium (Mg) contents. Fruit were stored for six months and quality attributes were studied. Results put forth that Ca+B treatments significantly increase fruit Ca and B concentrations and firmness. The results displayed that postharvest B spray improves Ca nutrition of fruits through synergism of Ca+B on Ca translocation.     

EFFECT OF EXTERNAL NITRATE CONCENTRATIONS ON NITRATE EFFLUX FROM ROOTS AND ACCUMULATION IN TWO BRASSICA NAPUS L. CULTIVARS

The nutrient solution was replaced on day 72 after sowing, and then the relationship between nitrate (NO₃)-nitrogen(N) concentration in plants and nitrate efflux from roots of two oilseed rape cultivars (Brassica napus L. cv. ‘Zhongyou 821’ (‘ZY821’) and “D89”) was compared on days 73, 74, and 75, respectively. Nitrate-N concentration in petioles of “ZY821” was significantly greater than in “D89”. Nitrate-N concentrations in the nutrient solution and petioles were high on day 73 and nitrate efflux from roots of “D89” was greater than from “ZY821”. On day 75, as nitrate-N concentrations in the nutrient solution declined, both the maximum cumulative efflux and efflux rate of “ZY821” was higher than “D89.” We hypothesized that “ZY821” could remobilize more nitrate-N from the petioles to meet its N needs. This would result in a decline in translocation of nitrate from roots to shoots and an increase in root cytoplasm nitrate concentrations and root efflux.     

TISSUE ELEMENT CONCENTRATIONS AND MINERAL REMOVAL RATES IN HONEYBUSH TEA I: CYCLOPIA GENISTOIDES

Results from a five year survey of honeybush (Cyclopia genistoides) in the Cape Floral Kingdom, South Africa, showed that concentrations of nitrogen, phosphorus, potassium, calcium and magnesium in the top growth of mature plants grown from seedlings were 1.29, 0.05, 0.53, 0.22 and 0.09%, respectively. Removal rates at each harvest were 8.23, 0.32, 3.38, 1.40 and 0.57 g of the respective elements per plant. These quantities were equivalent to 48% to 61% of the total mass of each element in the plant. Concentrations in the top growth of sodium, manganese, iron, copper, zinc and boron were, respectively, 1423, 16, 172, 5, 12 and 23 mg kg^?1. Seedlings of C. genistoides reached their peak mass around five years after planting, and attained higher dry masses in plantations than in the open veld. Mature, plantation-grown C. genistoides plants yielded around 638 g of top growth dry mass per plant at each harvest.     

TISSUE ELEMENT CONCENTRATIONS AND MINERAL REMOVAL RATES IN HONEYBUSH TEA II: CYCLOPIA SUBTERNATA

A survey of plantation-grown Cyclopia subternata showed that average concentrations of nitrogen, phosphorus, potassium, calcium and magnesium in the new top growth of mature seedlings and cuttings were 1.59, 0.09, 0.62, 0.32, and 0.17%, respectively. Respective removal rates of these elements at each harvest averaged 13.1, 0.7, 5.1, 2.6, and 1.4 g plant^?1. These quantities were equivalent to. 28% to 45% of the total element in the plant. Concentrations in the top growth of sodium, manganese, iron, copper, zinc and boron averaged, respectively, 1459, 34, 143, 7, 9, and 30 mg kg^?1. Old top growth dry mass and root dry mass increased with time. Peak new top growth yields from C. subternata plants derived from seedlings and cuttings differed by only 2.2%. At peak production, new growth constituted 15% of total seedling dry mass and 21% of total cutting dry mass.     

SEASONAL VARIATION AND THRESHOLD VALUES FOR CHLOROPHYLL METER READINGS ON LEAVES OF POTATO CULTIVARS

Chlorophyll meter readings below a threshold value would indicate the necessity to supply nitrogen (N) to the crop. This study aimed to determine threshold values for chlorophyll meter (SPAD) and nitrogen (N) rate effects on SPAD leaf measurements of potato cultivars through the crop cycle. Five N rates (0, 50, 100, 200, and 300 kg ha^?1) were evaluated in a randomized block design, with four repetitions. SPAD index was measured on the oldest (OL) and on the fourth leaf from the apex (FL) at 7, 14, 21, 28, 35, and 49 days after the emergence of 90% of the plants in the plots. SPAD values decreased with plant age and were influenced by N rates and leaf position. At 21 DAE, the SPAD threshold values on FL were 43.0, 44.6, 46.5, and 50.0 for ‘Agata’, ‘Monalisa’, ‘Atlantic’, and ‘Asterix’, respectively. The corresponding values were 41.9, 43.5, 49.9, and 49.9 on OL. Plant age and leaf position should be standardized for the assessment of SPAD threshold values to diagnose nitrogen status of potato cultivars.     

不同品种绿豆的品质及饮料加工特性研究

为研究绿豆品种品质差异并从中筛选适宜饮料加工的优良品种,本研究选取16个国内主栽绿豆品种,研究了品种的营养组成及制成饮料的营养、感官、稳定性等指标,并对原料与产品指标间的关系进行了相关性分析。结果表明,国产绿豆品种间的营养与加工品质特性存在不同程度的差异,绿豆原料组成中粗脂肪含量虽然较低,平均仅为1.33%,但变异系数较大,CV达到38.31%;淀粉、蛋白质平均含量分别达50.23%和27.08%,但品种间差异较小,CV仅4.53%和6.86%。不同绿豆品种所制备的饮料中,感官评分最高的为中绿1号(92分)。相关性分析结果显示,饮料中蛋白含量由原料中粗蛋白含量决定,两者呈极显著正相关(r=0.937**)。根据营养成分、稳定性和感官评价等指标,筛选出适合制作饮料的绿豆品种有:中绿1号、冀绿7号和白绿8号。     

NAA对大白菜吸收和积累~(45)Ca的效应

用ＮＡＡ处理大白菜根部和叶部,对其吸收和转运＾４５Ｃａ的变化进行了研究。结果表明,不论根部施用ＮＡＡ或叶面喷洒ＮＡＡ均使大白菜根对＾４５Ｃａ的吸收增加,提高茎叶＾４５Ｃａ的积累,尤其心叶中＾４５Ｃａ的积累显提高,同是改变心叶＾４５Ｃａ分布,使心叶叶缘的＾４５Ｃａ积累明显增加,且根部施用效果比叶面喷洒效果更明显。     

昆明地区主要花卉蔬菜基地设施栽培土壤养分变化特点

昆明地区蔬菜、花卉种植以设施栽培为主,本文对不同棚龄的大棚设施土壤pH、全N、P、K、碱解N、速效K、有效P、交换性Ca、Mg等指标进行测定分析,结果表明:随棚龄年限的增长,耕层土壤pH值、有机质和土壤交换性Ca、Mg含量有降低的趋势,但无论是露地还是盖棚土壤有机质(52.8 g/kg)都较20世纪80年代中期有较大幅度提高;耕层土壤和深层土壤,全N、有效N含量呈持续上升趋势。耕层土壤中,土壤速效K和速效P呈现明显的富集。     

冬小麦品种航天诱变后代性状分析

8个品种冬小麦的种子搭载实践8号育种卫星后经过连续多年种植选择,对其SP2、SP3代农艺性状及品质性状进行诱变效应分析。结果表明,小麦种子经航天诱变后能引起后代表现型的广泛变异,但不同品种、不同性状对空间环境的敏感性、诱变效果不同,SP2代新麦8、郑麦366的表现型突变频率分别达13.2%、12.5%。SP3代株高、穗...