新型胡萝卜奶片加工工艺研究

对具有营养保健功能的胡萝卜奶片的加工工艺进行初步探讨。结果表明:采用奶粉∶胡萝卜精粉为8∶2、葡萄糖25%、异麦芽低聚糖15%的原料配比,经混合、造粒、干燥、压片等工序制成了一款新型胡萝卜奶片。     

The Identification and Exploitation of Resistance in Carrots and Wild Umbelliferae to the Carrot Fly, Psila rosae (F.)

Partial plant resistance to the carrot fly, Psila rosae, has been identified in several Nantes varieties of carrot, Daucus carota, which reduces larval damage to the roots and the number of pupae remaining in the soil after cropping by 50%. The resistance of the Nantes variety 'Sytan' was found to be consistent at 12 sites in 5 European countries over two seasons. The resistance has been shown to be based on antibiosis and correlated with concentrations of chlorogenic acid in the roots. The resistance complements cultural and chemical methods for controlling P. rosae. Thus, in field experiments over two seasons it was shown that carrots could be left in the ground for a longer period providing a greater sowing/harvesting interval with a resistant variety than a susceptible one because of the reduction in damage and the delayed development of insects on the resistant variety. In two seasons at two sites a partially-resistant variety required only one-third of the dose of insecticide to provide a marketable crop compared with a susceptible carrot variety. In a breeding programme involving the variety 'Sytan', male sterile lines, inbreds and selections with improved levels of resistance were developed. Much higher levels of resistance were identified in certain wild Daucus species and 15 years of crossing and selection produced lines with significantly higher levels of resistance than exists in the variety 'Sytan'. A range of resistant carrot material bred at Horticulture Research International has been released to seed companies for use in the production of improved carrot varieties. The partially-resistant variety 'Flyaway' was made available to amateur gardeners in 1993 and to commercial growers in 1995 as a result of this research.     

Inhibitory effect of chitosan on growth of the fungal phytopathogen,Sclerotinia sclerotiorum,and sclerotinia rot of carrot

The antifungal activity of chitosan on a common fungal phytopathogen, Sclerotinia sclerotiorum, and the control effect on sclerotinia rot of carrot were investigated. Mycelial growth and fungal biomass were strongly inhibited by chitosan. Using propidium iodide stain combined with fluorescent microscopy, the plasma membrane of chitosan-treated S. sclerotiorum mycelia was observed to be markedly damaged. Concomitantly, protein leakage and lipid peroxidation was also found to be significantly higher in chitosan-treated mycelia compared to the control. Chitosan provided an effective control of sclerotinia rot of carrot, with induction of activity of defense-related enzymes including polyphenoloxidase and peroxidase. These data suggest that the effects of chitosan on sclerotinia rot of carrot may be associated with the direct damage to the plasma membrane and lipid peroxidation of S. sclerotiorum, and the elicitation of defense response in carrot.     

从长期继代培养的胡萝卜愈伤组织原生质体获得再生小植株

从继代3年以上的胡萝卜(Daucus carota var.sativa Dc.)非胚性愈伤组织酶解分离出大量成活的原生质体,在 DPD、V—KM 和 C81V 培养基中液体浅层培养,获得微愈伤组织后,在固体 N_6和 MS 培养基上分化培养,获得再生小植株。证明长期继代培养的胡萝卜愈伤组织仍具有再生植株的能力。     

胡萝卜肾形肾状线虫病的发生及药剂控制试验

从广东省番禺市胡萝卜根系及根际土分离到１种线虫,经鉴定为肾形肾状线虫,该线虫在胡萝卜的生长期内,以１０￣１１月份虫口密度最大,主要分布于０￣１５ｃｍ土壤层。该线虫危害胡萝卜,是国内胡萝卜上的１种新病害。药剂试验表明供试的几种杀线剂均对肾形肾状线虫有较好的控制作用,其中益舒宝复方Ｂ和Ｅ是值得生产上推广应用的杀线剂。     

In vitro antioxidant activity of callus culture of carrot （Daucus carom）

Carrot （Daucus carom） is a valuable source of health promoting ingredients such as anthocyanin, carotenes, phenolic compounds etc. These substances are important to man as a source of pharmaceuticals, fragrance, agrochemicals as well as food additives and used for prevention of many chronic diseases. Since these activities may be correlated with the presence of antioxidant compounds, extract of carrot and carrot callus were evaluated for their anthocyanin, flavonoids and total phenolic content as well as total antioxidant activity. Anthocyanin content was measured by spectrophotometric method. Total phenols and flavonoids were analyzed according to the Folin-Ciocalteu method and total antioxidant activity was assessed by ferric reducing/antioxidant power （FRAP） assay. Anthocyanin, flavonoids and total phenolic content were estimated to be 9.36 mg%, 46.96 mg% and 57.01 mg% for callus and 6.82 mg%, 32.96 mg% and 42.69 mg% for carrot, respectively, on fresh weight basis. The total antioxidant activity for the callus and carrot was found to be 51.13 mg, 118.77 mg, 91.08 mg and 140.08 mg equivalent and 79.40 mg, 184.44 mg, 141.43 mg and 217.52 mg equivalent to gallic acid, vitamin C, butylated hydroxyanisole （BHA） and trolox, respectively, when expressed per 100 g on fresh weight basis. The antioxidant activity of fresh carrot was found to be higher compared to its callus.     

Demonstration of secondary infection by Pythium violae in epidemics of carrot cavity spot using root transplantation as a method of soil infestation

Cavity spot of carrot (CCS), one of the most important soilborne diseases of this crop worldwide, is characterized by small sunken elliptical lesions on the taproot caused by a complex of pathogens belonging to the genus Pythium , notably P. violae . In most soilborne diseases the soil is the source of inoculum for primary infections, with diseased plants then providing inoculum for secondary infections (both auto- and alloinfection). Using fragments of CCS lesions to infest soil, it was demonstrated that CCS lesions on carrot residues can cause primary infection of healthy roots. Using a novel soil infestation method, in which an artificially infected carrot root (the donor plant) was placed close to healthy roots (receptor plants) the formation of typical CCS lesions were induced more efficiently than the use of classical soil inoculum and showed that CCS can spread from root to root by alloinfection from transplanted diseased roots. The method also demonstrated the polycyclic nature of a CCS epidemic caused by P. violae in controlled conditions. Secondary infections caused symptoms and reduced root weight as early as two weeks after transplantation of the diseased carrot. This reproducible method may be used for delayed inoculation and for studying the effect of cropping factors and the efficacy of treatments against primary and secondary cavity spot infections.     

丛枝菌根真菌Glomus mosseae单寄主培养体系的建立

 By using transformed Ri T-DNA carrot roots as host, the monoxenic culture of Glomus mosseae was successfully established. Some morphological processes of germination, colonization and spore formation, as well as bi-directional movement of hyphal cytoplasm flow were observed in this system.     

胡萝卜抗HgCl_2变异细胞系的筛选

利用胡萝卜下胚轴愈伤组织 ,以HgCl2 为选择剂 ,通过多步正筛选法 ,获得了抗性变异细胞系 .抗性鉴定结果表明 ,在不同HgCl2 浓度的培养基上 ,抗性系的愈伤组织存活率和鲜质量增殖率均明显高过亲本系 ,抗性系的细胞膜透性也发生了变化 .对抗性系和亲本系愈伤组织进行再分化的结果表明 ,在连续 3～ 4代的分化培养之后 ,愈伤组织都能再生绿苗 .提出了该项研究在预防和治理重金属污染方面的重要意义 .