不同草坪草体内类胡萝卜素含量的比较

用高效液相色谱仪,配以Waters Spherisorb(ODS-2封口的色谱柱,测定正常光照条件下沿阶草(Festuca arundinacea Schreb.)、高羊茅(Poapratensis L.)和草地早熟禾(Ophiopogon bodinieri Lévl.)体内类胡萝卜素的相对含量和构成.结果表明:主要类胡萝卜素按其在植物体内的含量多少排序为叶黄素>β-胡萝卜素≥紫黄质>新黄质;由于不同植物的类胡萝卜素/叶绿素的比值不同,所有类胡萝卜素均以其在整个类胡萝卜素中所占的比值的不同来衡量种间的差异;3种植物中的新黄质和β-胡萝卜素的含量没有明显差异;叶黄素与叶黄素库(包括紫黄质、单环氧玉米黄质和玉米黄质)呈明显的负相关关系,沿阶草叶黄素/叶黄素库的比值最高,而草地早熟禾和高羊茅之间没有明显差异;β-胡萝卜素及其衍生物(叶黄素库和新黄质)与α-胡萝卜素及其衍生物(叶黄素)的比值,在3种植物中具有显著差异,以草地早熟禾为最高,而沿阶草最低.     

FACE条件下水稻生育后期剑叶光合色素含量及产量构成的响应研究

为明确CO2浓度增高对水稻叶片光合能力的影响,利用自由CO2富集系统(free-air carbon dioxide enrichment,FACE)研究‘松粳9号’和‘稻花香2号’水稻生育后期剑叶光合色素含量及产量构成的变化趋势;通过测定水稻孕穗—抽穗期剑叶叶绿素a、叶绿素b和类胡萝卜素含量,分析光合色素组成、各组分间相关关系及品种间差异;收获后实测产量构成因素,比较处理及品种间差异。结果表明,与对照相比,高CO2浓度下水稻孕穗和抽穗期叶绿素a含量都极显著升高,‘松粳9号’和‘稻花香2号’的最大增幅分别达28.46%和19.58%;抽穗后20 d分别极显著降低15.25%和23.20%。高浓度CO2极显著降低水稻抽穗后20 d叶绿素b含量,两品种降幅分别为7.57%和5.33%;极显著增加抽穗后30 d叶绿素b含量,增幅分别为4.19%和9.46%。高CO2浓度下两品种水稻抽穗期类胡萝卜素含量显著增加9.47%和13.55%,抽穗后10 d之后显著降低,最高降幅达13.54%和16.67%。高CO2浓度下水稻总叶绿素含量和叶绿素a/b比值在孕穗和抽穗期增加,抽穗后20 d减少。高CO2浓度对产量构成因素均有正面影响,增加了水稻单位面积穗数、结实率和千粒重,显著提高了千粒重,两品种增幅分别达8.6%和4.5%。试验结果明确了高CO2浓度对水稻灌浆前期剑叶光合色素的积累有促进作用,后期有抑制作用,品种间响应差异显著;千粒重增加是增产的主要因素。     

番茄果实中类胡萝卜素合成与调控的研究进展

番茄是果实成熟研究中的模式植物,在番茄果实成熟过程中,类胡萝卜素种类与含量变化是影响果实着色和品质的重要因子,其相关研究也备受关注。本文综述了近年来国内外学者在番茄果实类胡萝卜素合成与调控等方面的研究进展,阐述了番茄果实中类胡萝卜素的种类、分布与含量,番茄果实在发育过程中类胡萝卜素的含量变化规律,以及参与类胡萝卜素合成的关键酶和转录因子等的研究进展,并对未来该热点问题的发展方向进行了展望。     

A deletion at the Lpx-B1 locus is associated with low lipoxygenase activity and improved pasta color in durum wheat (Triticum turgidum ssp. durum)

The concentration of yellow carotenoid pigments in durum wheat grain is an important quality criterion and is determined both by their accumulation and by their degradation by lipoxygenase enzymes (Lpx loci). The existence of a duplication at the Lpx-B1 locus and the allelic variation for a deletion of the Lpx-B1.1 copy is reported. This deletion was associated with a 4.5-fold reduction in lipoxygenase activity and improved pasta color (P<0.0001) but not semolina color, suggesting reduced pigment degradation during pasta processing. A molecular marker for the deletion was mapped on chromosome 4B in a population obtained from the cross between durum line UC1113 and variety Kofa. A second lipoxygenase locus, designated Lpx-A3, was mapped on the homoeologous region on chromosome 4A and was associated with semolina and pasta color (P<0.01) but not with lipoxygenase activity in the mature grain. Selection for both the UC1113 allele for Lpx-A3 and the Kofa Lpx-B1.1 deletion resulted in a 10% increase in yellow scores for dry pasta relative to the opposite allele combination. This result indicates that the markers and the new allelic variants reported here will be useful tools to manipulate the wheat Lpx loci and to improve pasta color.     

Chemical composition of wild and feral diploid wheats and their bearing on domesticated wheats

The diploid wild wheats Triticum monococcum ssp. thaoudar and Triticum urartu are the direct ancestors of all domesticated wheats, but almost nothing is known about the chemical composition of their kernels. Aim of this research was to assess their content in several compositional traits and to compare it with that of domesticated wheats. To this end, fifteen diploid, tetraploid and hexaploid accessions belonging to different Triticum species were tested for 1000 kernel weight, protein, ash and starch content, β-amylase activity, carotenoid, tocol, anthocyanin and polyphenol concentration. The wild einkorns had high protein (21.7 ± 0.74 g/100 g), ash (3.0 ± 0.06 g/100 g), tocol (75.1 ± 3.95 mg/kg), carotenoid (8.0 ± 0.91 mg/kg) and anthocyanin (43.0 ± 4.66 mg/kg) content, and low β-amylase activity (20.2 ± 0.84 B3U/g). T. urartu instead coupled high protein (28.0 ± 0.07 g/100 g), ash (3.3 ± 0.03 g/100 g) and tocol (63.9 ± 2.91 g/100 g) content with low carotenoid (2.7 ± 0.02 g/100 g) and high β-amylase (57.7 ± 0.11 g/100 g) levels. These results fit well with those observed in the derived wheats, i.e. domesticated and feral einkorn on one side and emmer, durum, spelt and bread wheat on the other. Several positive nutritional traits present in the diploid wild species were not lost during the transition from wild to domesticated forms.     

甘蓝叶球不同叶片叶绿素和类胡萝卜素含量变化研究

对3个甘蓝品种叶球不同叶位叶片的叶绿素、类胡萝卜素的含量变化研究表明,甘蓝叶球不同叶片叶绿素含量和类胡萝卜素含量变化趋势基本相似,由外向内其含量变化可分为3个区段:色素含量速减区、色素含量缓减区和色素含量近零区;叶绿素a、b及类胡萝卜素含量与叶绿素含量之间均呈现极显著的正相关,r≥0.989,其中叶绿素a对叶绿素含量的贡献最大;品种之间,叶球叶绿素总含量秦甘80表现最高,秦甘70次之,秦甘60最低,表明甘蓝品种间叶球叶绿素含量存在一定差异。     

不同采收期枸杞干燥过程中主要类胡萝卜素的变化

 【目的】通过分析了枸杞功能成分玉米黄素、β－胡萝卜素和主要酯化类胡萝卜素在干制加工中生物合成和降解规律，为改善加工条件，最大限度保存枸杞中类胡萝卜素，提高枸杞感观品质提供理论依据。【方法】采用反相高效液相色谱法、外标法定量测定不同采收期枸杞在干燥过程中主要类胡萝卜素的变化。【结果】干制起始阶段，玉米黄素、β-胡萝卜素含量大幅增加，是鲜果含量的2～22倍；干制中期，均有不同程度的降解，其中秋果的降解幅度较大；干制后期，两种色素含量有小幅增加并达到平衡状态。玉米黄素双棕榈酸酯在干制起始阶段全面降解，降幅达到40%以上；干制中期有小幅增加并最终达到稳定状态。夏果中的类胡萝卜素总量明显比秋果高。【结论】玉米黄素、β-胡萝卜素在枸杞干制后含量增加而酯化类胡萝卜素如玉米黄素双棕榈酸酯含量下降，从而对枸杞感观色泽产生影响。     

叶片类胡萝卜素在光氧化水稻品种间的差异

 以水稻叶片为材料，研究了光对类胡萝卜素组分的曩及其在受光氧化的水稻品种间的差异，结果表明，用薄层层析法可从水稻叶片中分离出各自具有不同颜色和独特吸收光谱的14个组分，不同作物和不同叶龄叶片的类胡萝卜素组分有差异，照光可使第8条带由绿转黄，其最大吸收峰移向长波方向，这是由于紫黄质向玉米黄质转变的结果，对光抑制敏感性不同的8个籼稻品种在低温、强光下培育15 d，表现类胡萝卜素组分降解不一样，不敏感品种的玉米黄质吸收峰值比敏感品种高出43.3%。这说明对光抑制的敏感性大小与处理期间叶片内玉米黄质形成的量有关。     

彩色甜椒果实转色期色素的消长规律

研究了4个果色不同的甜椒品种其果实叶绿素、类胡萝卜素、类黄酮和花青苷等色素在转色期的变化动态.结果表明,在果实转色期,不同果色的叶绿素含量均逐步减少,商品成熟果果色白色、绿色的品种类胡萝卜素含量逐步增加,且叶绿素的减少和类胡萝卜素的增加同时发生,而商品成熟果果色淡黄色的品种,类胡萝卜素含量逐步减少;不同果色品种的花青苷和类黄酮的变化规律相同,在果实转色期二者均逐步增长.     

植物生长调节剂处理对红肉脐橙果实着色的效应

于幼果期和果实转色前对红肉脐橙用不同浓度的外源ABA和GA3处理,分析了处理对红肉脐橙果皮着色的效应.结果表明：红肉脐橙果皮叶绿素总量于7月25日出现最大值（0.116mg/g FW）;总类胡萝卜素含量于12月25日达到最大值（0.029mg/g FW）;外源ABA处理后加速果皮叶绿素的降解,但也抑制了果皮类胡萝卜素的积累;GA3处理后延缓了果皮叶绿素的降解,并同样抑制了果皮类胡萝卜素的积累,阻碍了果皮类胡萝卜素的合成.