Sulphur fertilizer effect on cotton: I. Nitrogen and sulphur status and petiole nitrate‐nitrogen

Abstract

The effect of S fertilization on S and N status and petiole NO₃ ^?‐N in cotton was observed during the growing seasons of 1980 and 1981. Four sites representing 2 soil subgroups were studied using a randomized complete block design with 4 replications. Leaf and petiole sampling began one week prior to bloom initiation and continued weekly for eight weeks. Leaf samples were analyzed for S and N and the petioles for NO₃ ^?‐N. Levels of leaf‐S varied directly with amounts of applied S. Leaf‐N and petiole NO₃ ^?‐N varied directly with amounts of applied N. Though not always significant, petiole NO₃ ^?‐N and leaf‐N showed negative correlations with leaf‐S. These results suggest that knowledge of the cotton plant S status may be necessary to interpret petiole NO₃ ^?‐N for N fertilization of cotton.     

绿巨人叶柄的离体培养及其快速繁殖

绿巨人叶柄可以作为快速繁殖的外植体源。适宜的培养基，不定芽诱导为ＭＳ＋ＢＡ５．０ｍｇ／Ｌ（单位下同）＋ＮＡＡ０．２，继代和芽增殖为ＭＳ＋ＢＡ２．０＋ＮＡＡ０．２，生根培养为１／２ＭＳ＋ＮＡＡ０．２＋ＩＢＡ０．２。叶柄外植体培养过程中肿胀明显，表面变褐，但不影响愈伤组织和芽的启动。叶柄下端的芽诱导率比叶柄上端高２～３倍。     

Establishment of high frequency shoot regeneration system in Himalayan poplar (Populus ciliata Wall. ex Royle) from petiole explants using Thidiazuron cytokinin as plant growth regulator

Populus species are important resources for industry and in scientific study on biological and agricul-tural systems. Our objective was to enhance the frequency of plant regeneration in Himalayan popla...     

硝态氮难以在菠菜叶柄中还原的原因初探

【目的】蔬菜硝态氮过量累积危害人类健康，叶柄是蔬菜硝态氮累积的主要器官，揭示其累积硝态氮的原因是解决这一问题的关键。【方法】以3个菠菜品种为供试材料，设置不同氮水平进行盆栽试验，在不同生长期采样，测定叶柄硝态氮含量、内外源硝酸还原酶活性、细胞的硝态氮代谢库与贮存库大小，以及加入叶片硝酸还原酶后叶柄组织的亚硝态氮生成速率。【结果】叶柄硝态氮含量与其硝酸还原酶活性、代谢库大小无明显关系，但内外源硝酸还原酶活性的比值高、贮存库小，加入叶片硝酸还原酶后叶柄组织的亚硝态氮生成速率高的品种，其叶柄硝态氮含量低。【结论】叶柄潜在硝酸还原酶活性的实际表达程度、叶柄细胞液泡的大小、硝态氮由贮存库（液泡）进入代谢库（细胞质）的难易程度是造成硝态氮难以在叶柄中还原及品种间叶柄硝态氮含量差异的重要原因。     

大豆不同叶位叶柄维管组织的比较研究

大豆叶柄维管束划分为大、中、小三种类型。植株主茎第三复叶以下叶位叶柄中有五个大型和五个中型维管束并交错排列,第四——十四复叶叶位叶柄则有大、中、小型维管束并交互排列。不同叶位叶柄的大型维管束数目皆为五个,中部叶位叶柄具有较多的中小型维管束。中部叶位叶柄大中型维管束面积大于其他叶位叶柄。新品种比老品种具有较多的维管束数目和较大的维管束面积。维管束组织性状与饱和CO_2同化率具有较大的正相关。     

菊花脑离体培养再生植株研究

[目的]研究菊花脑离体培养再生植株技术。[方法]以菊花脑叶片、叶柄、茎段为外植体,以MS为基本培养基,研究了不同激素组合对其不定芽诱导率的影响。[结果]叶片外植体诱导率最高,叶柄次之,茎段最低。菊花脑叶片生芽的最佳培养基是MS＋1.0mg/L6-BA＋0.5mg/LNAA;叶柄生芽的最佳培养基为MS＋0.5mg/L6-BA＋0.5mg/LNAA;茎段生芽的最佳培养基是MS＋1.0mg/L6-BA＋0.5mg/LNAA。[结论]建立了菊花脑叶片、叶柄、茎段直接诱导不定芽的组织培养技术。     

多子芋叶柄及芽色的多样性及芋形观察

介绍了多子芋种质资源叶柄及芽色的多样性 ,总结了多子芋的叶柄颜色及芽色的对应关系及芋形的一般规律。叶柄为绿色或紫色时 ,芽为白色 ;叶柄为乌绿色时 ,芽为淡红色。叶柄紫色类的子孙芋芋形最好 ,卵圆形 ,且表皮棕毛少 ;叶柄绿色类和叶柄乌绿色类的子孙芋芋形较叶柄紫色类差 ,其中 ,叶柄绿色类的子芋芋形一般为头大尾小的卵圆形 ,表皮棕毛较多 ;叶柄乌绿色类的子芋一般为长卵圆形至卵圆形 ,且表皮棕毛较多。 3种类型的孙芋一般为卵圆形 ,且表皮棕毛少。芋形指数基本上反映了芋的实际形状。     

黑莓‘Kiowa’叶柄离体直接再生体系的建立

以黑莓品种‘Kiowa’无菌苗叶柄为外植体,研究了培养基类型、暗培养时间、着生位置、激素种类配比和生根条件等对叶柄不定芽诱导的影响,建立了叶柄直接再生体系。结果表明,把‘Kiowa’试管苗继代培养30～40 d后,取自上而下第1～2叶位的叶柄为外植体,接种在MS或1/2MS上,暗培养14 d或21 d叶柄的再生效果较好。‘Kiowa’叶柄不定芽再生的适宜培养基为MS+CPPU 1.0 mg/L+IAA 0.5 mg/L,不定芽再生率达87.46%,平均叶柄再生芽数目达4.42。芽增殖以MS+6-BA 0.5 mg/L+IAA 0.1 mg/L效果最好,增殖系数达5.19;再生植株生根以1/2MS+NAA 0.03 mg/L最佳,生根率达91.67%,平均生根条数为4.00。     

草莓叶柄和叶片的组织培养

用4种不同培养基配方对草莓叶柄和叶片进行组织培养.结果表明.MS+6-BA 0.5 mg/L+NAA 1.0 mg/L的愈伤发生率最高;处理MS+6-BA 0.5mg/L+NAA 2.0 mg/L的愈伤生长速度最快,MS+0.5 mg/L 6-BA+NAA 1.0 mg/L诱导芽分化及根形成最佳.     

Comparison of petiole nitrate concentrations,SPAD chlorophyll readings,and QuickBird satellite imagery in detecting nitrogen status of potato canopies

Nitrogen (N) management is critical in optimizing potato yield and quality and reducing environmental pollution. Six N rates from 34 to 270 kg ha⁻¹, and different timing of N application were used in a 3-year field experiment to contrast SPAD-502 chlorophyll meter and QuickBird satellite imagery data against the conventional petiole sampling technique for assessing canopy N status. Overall treatment variations in SPAD readings were consistent with those in petiole nitrate-nitrogen (NO₃-N) concentrations. However, the ability of the SPAD meter to detect treatment differences varied with growth stage and growing season. Severe N deficiency was detected about 1 month after emergence with SPAD readings, but as early as 2 weeks after emergence with petiole NO₃-N concentrations. Petiole NO₃-N concentrations tended to differentiate more treatment variations than SPAD readings at all growth stages except at hilling. N deficiency was detected with QuickBird image-derived vegetation indices (VIs) at the hilling stage in 2002, but not in 2003. At the post-hilling stage, treatment differences in VI values were minimal and insignificant except very late in the growing season. SPAD meters could be used as an indirect method for detecting N deficiency at the hilling stage when making supplemental N applications, but they are not as sensitive as the petiole sampling method. The sensitivity of QuickBird imagery to canopy N variations needs to be further tested with more pixel data. However, cloud interference and high cost of images could limit the use of QuickBird data in making timely management decisions.