胡萝卜、青刀豆低真空单层干燥研究

利用大型真空罐进行胡萝卜、青刀豆的单层干燥试验。综合考虑干燥速度和色素指标,得出胡萝卜和青刀豆的较佳罐温、胡萝卜较佳装载系数、物料层位置以及料块切割方式。讨论了低真空状态下温度不匀、切分对干燥的影响及膨化产生条件。     

胡萝卜种子高压静电场生物效应试验研究

利用高压静电场对胡萝卜种子进行筛选，并通过均匀设计安排试验，进行不同时间和电场强度的高压静电场处理，对胡萝卜种子的发芽势、发芽率、根长、苗高及鲜质重等指标进行测定，并对结果进行了回归分析和讨论，找出处理时间和电场强度的较佳取值组合。     

胡萝卜真空干燥工艺参数的试验研究

为了研究在真空干燥条件下胡萝卜的干燥特性．进而为其真空干燥确定适宜的工艺参数，选用5种真空度分别为0．05MPa、0．06MPa、0．07MPa、0．08MPa和0．09MPa，在4种干燥温度40℃、50℃、60℃和70℃条件下对鲜胡萝卜进行脱水干燥试验。测定不同干燥工艺条件下胡萝卜的干燥特性。并进行复水比较试验。试验结果表明：0．07MPa和60℃为胡萝卜真空干燥制的适宜工艺条件。复水最佳条件为温度60℃，时间为90min。     

外源GA3对高原夏季胡萝卜肉质根发育的影响

为了揭示外源GA3对胡萝卜肉质根发育的影响机理,并为高原夏季胡萝卜安全高效栽培技术研究提供参考理论,本试验以耐先期抽薹的胡萝卜品种为试材,采用酶联免疫吸附法(ELISA),研究了外源GA3对高原夏季胡萝卜肉质根膨大、木质化及其内源激素含量的影响。结果表明,在叶片旺盛生长期和肉质根迅速膨大期分别喷施5.78×10-4 mol·L-1外源GA3 1次,或在苗期、叶片旺盛生长期和肉质根迅速膨大期喷施5.78×10-4 mol·L-1外源GA3 1~3次,能显著降低高原夏季胡萝卜苗期肉质根日鲜重增长速率与库活力,促进肉质根木质化。与对照相比,喷施外源GA3,可显著降低苗期肉质根内源GA3、IAA、GA4、ABA、DHZR与IPA含量,显著提高肉质根内源ZR含量;显著降低叶片旺盛生长期肉质根内源GA3、IAA、GA4、IPA含量,显著提高内源ZR含量;显著提高迅速膨大期肉质根内源IAA、GA4、ZR含量;显著降低肉质根迅速膨大期之前的IAA/ZR和GA4/ZR比值。随着外源GA3喷施次数的增多,IAA/ZR和GA4/ZR比值在肉质根迅速膨大期有逐渐增高的趋势。外源GA3通过改变内源激素含量及其平衡状态来影响高原夏季胡萝卜肉质根的发育。     

人乳铁蛋白基因转化胡萝卜研究初报

乳铁蛋白具有抗菌、抗病毒感染和促进 Fe吸收等多种功能 .把人乳铁蛋白基因转入胡萝卜 ,为其添加新的营养保健因子 ,同时增强植株抗性 ,具有重要意义 .本试验把人乳铁蛋白基因插入 p BIN1 2 1质粒 Xba 、Sac 位点之间 ,经农杆菌介导 ,转入胡萝卜受体 ,在抗性筛选培养基上诱导形成抗性愈伤组织 ,进而经胚状体途径得到抗性苗 .经 PCR检测 ,初步确定抗性植株为转人乳铁蛋白基因植株     

胡萝卜单根重杂种优势和主要经济性状配合力分析

以5个胡萝卜雄性不育系为母本,6个胡萝卜品种或自交系为父本配制30个杂交组合,杂种一代调查结果表明:单根重具有明显的杂种优势,绝大多数组合表现超亲中值或超高亲现象。通过对单根重、根长、根粗、根色、根髓比和可溶性固形物的配合力分析,认为组合A2×B5在育种上最具应用价值。     

胡萝卜悬浮细胞原生质体的培养研究

继代培养 4～ 5d后的胡萝卜悬浮细胞 ,经酶解获得大量原生质体 ,并在不同的培养基上培养 ,探讨了影响原生质体培养的多种因素。实验表明 :①原生质体的培养密度在 5× 1 0 4 mL～ 5× 1 0 5 mL范围内均可 ,以 2 5× 1 0 5 mL为佳 ;②对于细胞的分裂、细胞团的生长 ,以改良的B5培养最好 ,N6培养其次 ,MS较差 ;③适当降低原生质体培养基中的甘露醇浓度 ,有利于细胞的分裂和生长 ;④在本实验所涉及的培养方法之中 ,以液体浅层培养为优。     

Assessment of Disturbances in Growth and Physiology of Carrot Caused by Chromium Stress

To see the deleterious effects of excess chromium (Cr) on carrot (Daucus carota L.) the cv. ‘Pusa Keshari’ was grown in refined sand under controlled glasshouse conditions with a complete nutrient solution (without Cr) for 48 days. On the 49th day, pots with two plants each were separated into three sets. One set served as a control. In each of the other two sets, Cr was supplied as dichromate at 0.1 and 0.5 mM to the basal nutrient solution. At 0.5 mM Cr toxicity symptoms appeared at d 52 (4 days after Cr supply) as reduction in growth and leaf size and loss of turgor. Old leaves became chlorotic and wilted. Chlorosis intensified and turned necrotic in another few days. These symptoms spread to next upper leaf. The development of chlorosis in leaves was delayed in plants receiving 0.1 mM Cr. At excess Cr (0.5 mM) in carrot, the biomass, concentration of chlorophylls a and b, iron (Fe), sulfur (S), and phosphorus (P) in shoots, and activity of catalase (CAT) in leaves decreased whereas the concentration of Cr and the activity of peroxidase (POX), superoxide dismutase (SOD), ribonuclease (RNAse), and acid phosphatase (A P) in leaves increased.     

Aluminum-tolerance of carrot (daucus carota L.) plants regenerated from selected cell cultures

Abstract

Aluminum-tolerant variants from cell cultures of carrot (Daucus carota L. cv. MS Yonsun) were selected by exposing them to excess ionic aluminum. The medium contained A1CI₃ and 0.1 mM phosphate at pH 4.0. Under ionic aluminum stress (0.5-1.0 mM), 282 calli were selected. Twenty-eight fertile plants were regenerated from 7 selected calli. Based on the root elongation tests of the seedlings, the seeds displayed aluminum-tolerance. In the case of the cell line H7-08, the selection occurred at a frequency of ca. 6 × 10^-7 when the materials were plated on agar medium containing 0.5 mM aluminum.     

Freezing Tolerance Affected by Mineral Application during Cold‐Acclimated Conditions in Some Cool Crop Seedlings

Abstract

The effect of mineral nutrient application on freezing tolerance in red cabbage, carrot, and spinach under cold‐acclimated and unacclimated conditions were evaluated in this study. Effects of nutrient‐solution application and cold acclimation on temperature at which 50% of leaves are injured (LT₅₀), values, and ice nucleation activity in all of the plants were found to be statistically significant. Nutrient‐solution applications decreased LT₅₀ values in all of the species under unacclimated and cold‐acclimated conditions. Freezing injuries in cold‐acclimated plants were significantly lower than in unacclimated plants in all of the nutrient application doses. In addition to this, 600–900 mg l^?1 nutrient solutions also gave low plant injury in all conditions. Nutrient‐solution applications increased ice nucleation temperatures of apoplastic proteins, proline, and total chlorophyll contents in all of the plant species under unacclimated and cold‐acclimated conditions. Among the plant species, carrot was the most resistant plant to freezing injury under all nutrient application doses in the tested conditions.