胡萝卜愈伤组织诱导培养的研究

以胡萝卜"七寸人参"为试材,探讨了不同外植体、激素、培养基、光照对胡萝卜愈伤组织诱导的影响。结果表明:胡萝卜愈伤组织的诱导以下胚轴为外植体为宜;在添加2,4-D1.0mg/L和KT 0.5mg/L的MS培养基上愈伤组织的诱导频率为100%,且愈伤组织生长良好,增殖快速;光照对愈伤组织的诱导没有影响,但却进一步阻碍了愈伤组织的增殖生长。     

甜橙-胡萝卜汁复合饮料加工工艺研究

以重庆甜橙和胡萝卜为原料,采用多次配方试验,研究其复合饮料的生产工艺和加工技术。结果表明,甜橙汁与胡萝卜汁的体积比为1:9,以35%的原汁含量和12%的可溶性固形物生产的复合饮料的营养物质损失较少,口味优良、品质俱佳。     

凝固型胡萝卜风味酸奶的研制

胡萝卜酸奶是以胡萝卜浆、牛奶、白砂糖为主要原料,通过调配、均质、杀菌、发酵等加工工艺而制成的一种风味优良、营养丰富的酸奶制品。实验结果表明,在牛乳中加入20%的胡萝卜浆,8%的蔗糖,0.6%的复合稳定剂(果胶∶CMC=1∶1),经90℃,10min保温杀菌后,接入4.5%的乳酸菌,在42℃下培养4h,最后在4～10℃条件下后熟24h,即可得到优质的胡萝卜酸奶制品。     

5-氨基乙酰丙酸对种绳模式播种胡萝卜生长及品质的影响

研究不同浓度的外源5-氨基乙酰丙酸对种绳胡萝卜生长及品质的影响,以期为5-氨基乙酰丙酸在胡萝卜上的应用提供理论依据。本研究以种绳模式播种的‘黑田5寸参’胡萝卜为试验材料,在胡萝卜生长季节向胡萝卜叶面喷施不同浓度的5-氨基乙酰丙酸(10、25、50、100 mg/L),收获后通过测定胡萝卜的根长、根粗、根重、叶长以及叶绿素、可溶性蛋白、可溶性固形物、胡萝卜素含量等形态和生理指标来评价胡萝卜的产量和品质。结果表明,10~50 mg/L的外源5-氨基乙酰丙酸可以提高胡萝卜的株高和叶片中叶绿素的含量,与对照（不喷施5-氨基乙酰丙酸）相比,根重、根长、根粗和干物质含量分别增加73.05%、15.56%、18.75%和25.31%。此外,低浓度的外源5-氨基乙酰丙酸还提高了胡萝卜肉质直根中可溶性固形物、可溶性蛋白及胡萝卜素的含量,较高浓度的5-氨基乙酰丙酸则抑制了胡萝卜的生长,降低了胡萝卜肉质直根的品质。50 mg/L的5-氨基乙酰丙酸在促进胡萝卜生长和改善品质方面表现最好,可以为胡萝卜生产实践提供参考和借鉴。     

胡萝卜缨果拉拽式分离装置设计与试验

为了获得胡萝卜缨果拉拽式分离装置最优设计参数,以获取最佳分离效果,建立了拉拽式缨果分离装置运动学模型,定性分析了相关参数对拉拽杆运动学特性的影响。设计了胡萝卜缨果拉拽式分离试验台并进行了缨果分离正交试验,经分析发现拉拽杆的转速对胡萝卜缨果分离效果影响最大,拉拽杆与输送带的夹角对胡萝卜缨果分离效果的影响显著;同时得到了胡萝卜缨果分离装置的最佳参数组合:拉拽杆转速为200 r/min、输送带线速度为1.2 m/s、拉拽杆与输送带夹角为40°,此时缨果分离的一致性为97%,成功率为94%,损伤率为7.7%。     

不同地膜覆盖对土壤温度和胡萝卜营养生长的影响

在大田条件下研究了不同地膜覆盖对土壤温度和胡萝卜生长发育的影响.结果表明:在胡萝卜的营养生长阶段,透明膜和黑色膜覆盖对土壤均有明显的增温效应,日均土壤温度分别比对照提高4.34℃和3.33℃.透明膜和黑色膜覆盖后有效促进了胡萝卜肉质根的生长发育,播种后110d时,单根质量分别比对照提高39.97%和12.64%,同时营养生长期分别比对照提前32d和19d,且透明膜总体效果优于黑色膜.     

Nucleotide polymorphism in the carrot late embryogenesis abundant gene DC8/ECP63

Carrot (Daucus carota) somatic embryogenesis has been extensively used as an experimental system for studying embryogenesis. In several plant species, late embryogenesis abundant (LEA) genes are reported as the embryogenesis-related genes that are specifically expressed in embryonic tissues. Several LEA genes have been isolated for carrot somatic embryogenesis. The carrot LEA genes DC8 and ECP63 have very similar nucleotide sequences, and the gene pair is likely to be a nucleotide polymorphism. In several carrot cultivars, plants in which only DC8 was detected (DD genotype), only ECP63 was detected (EE genotype), and both DC8 and ECP63 were detected (DE genotype) have been observed via genomic PCR. Furthermore, distinct frequencies of the genotypes were observed in some carrot cultivars. These results suggested that detection of the nucleotide polymorphism might be useful in defining carrot cultivars. In addition, DC8 and ECP63, which include 14 amino acid insertions/deletions and 21 amino acid substitutions, may have similar effects on somatic embryogenesis, as all genotypes (DD, DE, and EE) were detected in some embryogenic cell lines. Therefore, the nucleotide polymorphism may be a useful candidate polymorphic marker that is easily detectable by PCR.     

两种胡萝卜外植体无性系培养比较研究

分别以具有潜在有利变异性状的胡萝卜的根及丛生芽为外植体,比较了不同外植体获得无性系的灭菌方法和分化增殖生根的激素配比.结果表明,不同外植体的灭菌方法差别较大:用肉质根做外植体时,促进产生愈伤组织效果最好的培养基为MS+6-BA 0.1 mg/L+2,4-D 0.1 mg/L,促进芽分化增殖效果最好的培养基为MS+6-B...     

Phylogeny and relationships in Daucus based on restriction fragment length polymorphisms (RFLPs) of the chloroplast and mitochondrial genomes

Chloroplast DNA (cpDNA) restriction site analysis of nine species of Daucus (covering four of five sections) and nine carrot accessions was done using 14 Petunia cpDNA clones as probes and 10 restriction enzymes. Cladistic analysis yielded a phylogeny generally concordant with a recent morphological classification. A cpDNA insertion-deletion mutation was found in the cultivated carrots (probe P10– Bgl II digest). Mitochondrial DNA (mtDNA) restriction site analysis of the same material using four maize mtDNA clones as probes and 10 enzymes exhibited extensive mitochondrial diversity in Daucus, both within and between sections. This revised version was published online in July 2006 with corrections to the Cover Date.     

Dehydration of gluten matrix as a result of dietary fibre addition – A study on model flour with application of FT-IR spectroscopy

Nowadays, consumers demand dietary fibre-enriched products of appropriate taste, texture, smell and appearance. Unfortunately, addition of the dietary fibre supplements to bread significantly reduces its quality which is connected with changes in the structure of gluten proteins. Structural changes as well as changes in the water state of gluten matrix induced by eight dietary fibres were observed by using Fourier transform infrared spectroscopy. To facilitate this the difference spectra were calculated by subtraction of the control (gluten only) infrared spectrum from the spectra of gluten-fibre mixtures. The presence of positive bands at ca. 1597 and 1235 cm⁻¹ indicated aggregation of gluten proteins into hydrogen bonded β-sheets. These β-sheets can be formed by other β-sheets, antiparallel-β-sheets, β-turns and/or α-helices. The aggregation is probably induced by partial dehydration of gluten matrix due to competition for water molecules between gluten proteins and fibre polysaccharides. This assumption is confirmed by the presence of the negative band at 3237 cm⁻¹ and decrease in the intensity of the band at 3051 cm⁻¹. These bands are assigned to the weak and strong H-bonds in the gluten matrix, respectively. The results indicated that both weak and strong H-bonds are necessary to dough formation of adequate rheological properties.