Effects of β‐carotene‐enriched dry carrots on β‐carotene status and colostral immunoglobulin in β‐carotene‐deficient Japanese Black cows

Data from 18 β‐carotene‐deficient Japanese Black cows were collected to clarify the effects of feeding β‐carotene‐enriched dry carrots on β‐carotene status and colostral immunoglobulin (Ig) in cows. Cows were assigned to control or carrot groups from 3 weeks before the expected calving date to parturition, and supplemental β‐carotene from dry carrots was 138 mg/day in the carrot group. Plasma β‐carotene concentrations in the control and carrot groups at parturition were 95 and 120 μg/dL, and feeding dry carrots slightly improved plasma β‐carotene at parturition. Feeding dry carrots increased colostral IgA concentrations in cows and tended to increase colostral IgG₁, but colostral IgM, IgG₂, β‐carotene and vitamin A were not affected by the treatment. Feeding dry carrots had no effects on plasma IgG₁, IgA and IgM concentrations in cows, but plasma IgG₁ concentrations decreased rapidly from 3 weeks before the expected calving date to parturition. These results indicate that feeding β‐carotene‐enriched dry carrots is effective to enhance colostral IgA and IgG₁ concentrations in β‐carotene‐deficient cows.     

胡萝卜主要产量性状杂种优势及配合力分析

以３个不育系为母本，４个自交系为父本，按不完全双列杂交法配制１２个组合，进行杂种优势和配合力分析。结果表明，小区产量、单根重、根长和根粗均表现了明显的正向杂种优势，以小区产量和单根重的杂种优势较高；亲本一般配合力效应比组合特殊配合力效应更为重要，其中父本的作用大于不育系的作用；３０株系（Ｂ_３）小区产量、单根重、根长和根粗的一般配合力具有较大的正向效应值，丹富士分离株系（Ａ_２）心柱比例具有较大的负向效应值。从根形、根色及整齐度来看以丹富士分离株系（Ａ_１、Ａ_２）作母本，Ｂ_３为父本更为理想。     

Influence of treatment of soil with carbofuran on the subsequent performance of insecticides against cabbage root fly (Delia radicum) and carrot fly (Psila rosae)

A sandy loam soil was treated with 2·5 kg carbofuran/ha on each of five occasions between May and October 1984. In 1985, the field performance of benfuracarb, carbofuran, carbosulfan, chlorfenvinphos and furathiocarb against cabbage root fly (Delia radicum) and carrot fly (Psila rosae) was studied in this soil and in identical but previously untreated soil by applying exponentially increasing doses of granular formulations to radish and carrots at drilling. Chlorfenvinphos reduced numbers of larvae of both pests by >90% in both soils but the performance of all the carbamates was significantly worse in the previously treated soil than in the previously untreated soil. Dazomet, a partial soil sterilant, was applied to part of the experimental area in October 1985 and the performance of aldicarb, carbofuran, carbosulfan, chlorfenvinphos and thiofanox against cabbage root fly was assessed in 1986. The efficiency of aldicarb and chlorfenvinphos was not affected by any of the pre-treatments but that of carbofuran and carbosulfan was reduced in all the pre-treated soils, including the soil treated with dazomet. Carbofuran residues in radish were detectable only in plants grown in previously untreated soil. In laboratory incubations, a dustless base formulation of carbofuran was degraded more quickly in pre-treated than in untreated soils but a granular formulation was degraded more slowly and at a similar rate in both soils.     

胡萝卜抗冻蛋白的快速与高效纯化

将胡萝卜抗冻蛋白在大肠杆菌中进行表达后．对获得的包涵体进行了初步的洗涤纯化．分别采用HPLC和Native PAGE法对其进行最终的纯化．结果表明．两种方法都能获得高度纯化的目的蛋白．而且耗时都很少．但Native PAGE法更为经济．且可以同时进行多个样品的纯化．更适用于一般实验室．     

Occurrence of Pythium Ultimum Var. Ultimum in a Greenhouse on Spitsbergen Island, Svalbard

Pythium ultimum var. ultimum was isolated from carrot seedlings with damping off and from soil used for growing the plant in a greenhouse on Spitsbergen Island, Svalbard. The fungus caused severe damping off of carrot, cucumber and tomato seedlings after artificial inoculation. The rDNA internal transcribed spacer sequences of the Svalbard isolate were identical to those of Canadian and Japanese isolates of P. ultimum var. ultimum. The results suggest that the pathogen in the greenhouse on Svalbard was probably introduced from temperate regions through contaminated plants and/or soil imported to the island. This is the first record of P. ultimum var. ultimum within the Arctic zone.     

中稻─胡萝卜一年两熟高产高效栽培技术

宁化县曹坊乡近年在不同海拔地块进行中稻—胡萝卜一年两熟高产示范栽培,取得全年产值约8000元/667m2的显著效益。介绍了中稻—胡萝卜一年两熟高产高效栽培技术。     

丛枝菌根真菌与胡萝卜毛状根双重培养体系研究

以发根农杆菌（Agrobacterium rhizogenes）K599诱导胡萝卜产生毛状根,接种丛枝菌根（AM）真菌摩西斗管囊霉（Funneliformis mosseae）建立双重培养体系,研究不同消毒方法、超声波、低温预处理和培养基pH对摩西斗管囊霉孢子萌发的影响及其与胡萝卜毛状根建立双重培养体系的最佳条件。研究结果表明：消毒方法3孢子萌发率最高,孢子污染率最低,15 d孢子萌发率达48.88%,而污染率仅为9.98%;超声波处理能降低孢子污染率11.17%~14.53%;低温预处理可有效提高孢子的萌发率,4℃低温处理10 d和15 d效果较好,其萌发率分别为70%和65%;AM真菌孢子在水琼脂培养基萌发最佳pH为6.5,萌发率达到48.50%,pH< 5.5或pH>8.0均抑制孢子萌发,pH 5.5和pH 8.0的萌发率分别为15.43%和16.06%。消毒孢子先于水琼脂萌发后,再挑取萌发管多,菌丝较长的孢子并将菌丝生长方向正对毛状根方向进行转接,可以提高双重培养的成功率。MSR培养基为双重培养的最优培养基。胡萝卜毛状根与AM真菌双重培养可为菌根真菌繁殖及相关分子机理研究提供可行有效的途径。     

胡萝卜抗冻蛋白的快速大量突变及原核表达

胡萝卜抗冻(DcAFP)具有典型的LRR特征,由约24个氨基酸残基组成重复单元,其中的保守基序是:P×××××L××L××L×LS×N×L×G×I,其中的保守天冬酰胺在与冰晶表面结合中起着关键的作用．为了探明该关键氨基酸对DcAFP重要性,需要对其进行一系列突变,以检测这些突变体的热滞可能发生的变化,而这需要构建大量的突变体．基于此,采用定点突变技术对该基序中保守的天冬酰胺进行了一系列的疏水性缬氨酸突变和亲水性的谷氨酰胺突变,并将这一系列突变体克隆至原核表达载体pET-11a中,在大肠杆菌BL21(DE3)中进行了高效表达与初步纯化,为后续测定其热滞活性的变化和验证天冬酰胺的重要性打下了基础．     

胡萝卜鱼糕的研制及其品质研究

为改善传统鱼糕的风味,研制出含胡萝卜质量分数为10%的新型鱼糕,并对其持水性、色泽和质构等品质指标进行检测。结果表明,与传统鱼糕相比,胡萝卜鱼糕明度(L)和白度(W)显著减小,红色度(a)和黄色度(b)显著升高,色泽更加鲜艳;硬度、胶黏性、咀嚼性显著降低,更好咀嚼,质感更鲜嫩。     

鲜切胡萝卜的真空预冷研究

研究了不同切片厚度与预冷终温对鲜切胡萝卜真空预冷效果的影响,分析了经过真空预冷和未经真空预冷的鲜切胡萝卜在贮藏期内的呼吸强度、失重率、色差和硬度的变化。结果表明,鲜切胡萝卜可比完整胡萝卜节省2/3的预冷时间;在切片厚度6 mm和预冷终温6℃时,鲜切胡萝卜的真空预冷效果最佳,失重率为1.3%、芯部温度1.5℃、预冷时间7.3 min。采用真空预冷处理方法可有效抑制鲜切胡萝卜贮藏期内的呼吸强度,降低失重率,保持其较好的感官品质。