New insights into the carotenoid biosynthesis in Torreya grandis kernels

Torreya grandis is a characteristic rare economic tree species in subtropical mountainous areas. The nut has a variety of bioactive compounds, such as polyphenols and vitamins. However, the carotenoids compositions and its regulatory mechanisms underlying carotenoid biosynthesis in kernels remain unknown. Here, the major carotenoids in the kernel were analyzed. The result showed that lutein and β-carotene were the predominant carotenoids in the kernel, while low levels of a-carotenoid and zeaxanthin were detected. Lutein and β-carotene were decreased during the maturation of kernel. Expression analysis by RNA-seq and q RT-PCR indicated that the expressions of TgCYP97A3 and TgLCYB were also reduced during the maturation of kernel. The contents of lutein or β-carotene were obviously increased in tobacco transiently overexpressing TgCYP97A3 or TgLCYB. Moreover, DPPH radical scavenging activity and FRAP were also significantly enhanced. In addition, several MYB and WRKY transcription factors TgMYBS3, TgMYB48 and TgWRKY11 were identified to positively regulate the TgCYP97A3 expression, while TgMYB48, TgWRKY2 and TgWRKY11 could upregulate the TgLCYB expression. The illustration of carotenoids biosynthesis and its molecular mechanism in kernels not only provides a basis for understanding carotenoids biosynthesis in kernels, but also enables the use of molecular biotechnology to develop new health products rich in carotenoids based on T. grandis nuts.

Effects of Torreya grandis Root Rot on Seedling Growth and Screening of Its Chemical Control Agents

[Objectives]This study was conducted to prevent the occurrence of root rot disease in Torreya grandis and improve the yield and quality of T.grandis.[Methods]One-year-old and two-year-old seedlings of Torreya grandis‘Xifei’and‘Cufei’were inoculated with the root rot pathogen Fusarium fujikuroi,and the changes in photosynthesis,chlorophyll content,malondialdehyde,and defense enzyme system(superoxide dismutase,peroxidase,and catalase)activity in leaves of T.grandis seedlings were investigated using water as a control.Meanwhile,the control effects of 80%carbendazim wettable powder,64%metalaxyl·mancozeb wettable powder,430 g/L tebuconazole suspension and 30%difenoconazole·cyproconazole EC on root rot in T.grandis were investigated.[Results]After inoculation with the pathogen F.fujikuroi,the net photosynthetic rates and transpiration rates in leaves of T.grandis‘Xifei’and‘Cufei’decreased,and the contents of chlorophyll decreased,while the contents of malondialdehyde increased,and the contents of superoxide dismutase and catalase increased with time.However,peroxidase showed a high activity in T.grandis‘Cufei’only,but a trend of"increasing-decreasing-increasing"in T.grandis‘Xifei’.Among the four chemical control agents,64%metalaxyl·mancozeb wettable powder had the best control effect on root rot of T.grandis caused by the pathogenic fungus F.fujikuroi.[Conclusions]The net photosynthetic rate,transpiration rate,chlorophyll content,malondialdehyde content,superoxide dismutase activity and catalase activity could all be used as screening indicators for T.grandis varieties resistant to root rot.Meanwhile,64%metalaxyl·mancozeb wettable powder could be used as a control agent for root rot on T.grandis.

Chinese Torreya grandis cv.Merrillii seed oil affects obesity through accumulation of sciadonic acid and altering the composition of gut microbiota

Torreya grandis cv.Merrillii(Taxace,Torreya)is mainly distributed across the hilly areas of subtropical China and is well known for its nutritional value.In this study,the ameliorative effects of T.grandis seed oil on lipid metabolism were investigated,and the underlying mechanism was explored from the perspective of gut microbiota.Mice experiments showed that the rate of body mass gain in the group where the mice were fed a high-fat diet(HFD)and supplemented with 550 mg/(kg·day)T.grandis seed oil(HFD+TO550 group)was 42.27%,while it was 62.25%in the HFD group.Compared with the HFD group,the liver and fat indices,total cholesterol,triglycerides,and low-density lipoprotein cholesterol were reduced in the oil-supplement groups.Moreover,the oil supplement significantly changed the fatty acid composition and alleviated pathological damage to the liver caused by the high-fat diet.Additionally,the distinct clustering of bacteria in the composition of gut microbiota was observed in the oil treatment group compared with that in the HFD group.T.grandis seed oil significantly increased the abundance of the beneficial bacteria and short-chain fatty acid producers,including Lactobacillus,Bifidobacterium,Faecalibaculum and Allobaculum.Our results suggest that the supplements of T.grandis seed oil could alleviate hyperlipidemia caused by HFD.These positive effects are considered to be related with sciadonic acid(SCA)and are partially mediated by alterations in gut microbiota composition and functionality.

Nutrients Determination in Nuts from Different Torreya grandis Cultivars

[Objectives]This study aimed to investigate the differences in nutritional properties of nuts from different Torreya grandis cultivars.[Methods]Seven T.grandis cultivars were selected to analyze the protein,soluble carbohydrate,vitamin E,amino acids and fatty acid composition,and evaluate nutritional value of T.grandis nuts from different cultivars using gray correlation analysis.[Results]The kernels of T.grandis contained 9.47%-13.3% protein,1.92%-2.36% soluble carbohydrate,0.16-0.22 mg/g vitamin E,8.40%-11.55% amino acids,and 42.09%-49.29% fatty acid including 35.14%-40.14% oleic acid.And the coefficient of variation ranged from 5.02% to 18.9% among different cultivars.Meanwhile,the average contents of essential amino acids(E),nonessential amino acids(N)and children essential amino acids(C)were 3.88%,6.07% and 0.99%,respectively.The ratios of E/T and E/N were quite stable and in fully compliance with the recommendation standards of amino acids composition from WHO/FAO.[Conclusions]Overall,the nutritional value of tested seven cultivars could be ranked in the following decreasing order using gray correlation analysis:T.grandis cv.Dong No.2>T.grandis cv.Longfeng>T.grandis cv.Dingshan>T.grandis cv.Merrilli>T.grandis cv.Dong No.3>T.grandis cv.Dong No.1>T.grandis cv.Zhuyan.

Protection and development of agricultural heritage from the perspective of stakeholders

Based on the stakeholder theory,field interviews and surveys were carried out among 332 stakeholders of Shaoxing ancient Torreya grandis groups,including local government,tourists,tourism enterprises,local residents and heritage inheritors.This paper aims to analyze the main demands of various stakeholders,and the cognitive and interest demands,by means of SPSS23,in the process of agricultural cultural heritage protection and tourism development.It is believed that the local resources endowment is favorable,but the tourism development and the protection of agricultural cultural heritage are in a state of separation,or even opposition.Therefore,the corresponding development countermeasures should be put forward from the common interest appeal of the five core interest groups.

香榧枝叶黄化的生理生化特性及土壤理化性质分析

本研究以二十年生的正常和不同黄化程度的香榧为试验材料,测定一、二年生枝叶的叶绿素含量、光合特性、抗逆性指标、矿质元素含量以及土壤的理化性质,利用单因素方差分析、双因素方差分析和相关性分析来分析香榧枝叶黄化后生理上的变化及导致黄化的因素。黄化香榧叶片叶绿素含量显著低于正常香榧(P<0.05);净光合速率、蒸腾速率、气孔导度等都随着黄化的加重呈下降趋势,胞间二氧化碳浓度则呈上升趋势;枝叶的SOD、POD、APX活性和PRO、MDA含量黄化时较正常时均显著升高。随着黄化程度加深,枝叶中氮、锌、锰、硼含量呈显著上升趋势(P<0.05),铜、镁含量呈显著下降趋势,黄化香榧的土壤中全量氮、有效锌、全量锌、全量锰的含量显著高于正常香榧(P<0.05),pH值显著低于正常香榧。相关性分析表明香榧枝叶黄化是多种元素综合作用的结果。由此可知,黄化明显降低叶绿素含量和光合速率、引起了香榧的抗逆性响应、造成了叶片的氧化损伤;氮、锌、锰含量过高,镁、铜含量偏低、土壤偏酸性可能是导致香榧枝条黄化的主要原因,研究结果为今后香榧黄化的防治提供参考价值和理论基础。

基于ISSR标记的16份榧树种质亲缘关系分析

榧树(Torreya grandis)为中国特有的优良经济树种,种质资源十分丰富,揭示种质间的亲缘关系有利于对其进行有效保护与利用。采用ISSR分子标记技术,对16份榧树种质亲缘关系进行分析。通过对100条引物的筛选,获得13条重复性好且多态性高的引物,经扩增共得到75条清晰可辨条带,其中多态性条带41条,总多态性条带百分率P为54.67%,平均为57.04%。每条引物扩增条带数介于2~13条,平均5.77条。16份榧树种质总Shannon信息指数I为0.2309,平均为0.2428;总Nei基因多样性(H)为0.1459,平均为0.1535。P、I、H均表明16份榧树种质总体水平的遗传多样性较高。16份榧树种质的遗传距离介于0.0270~0.3857,平均为0.1722;遗传相似度介于0.6800~0.9733,平均为0.8443。根据遗传距离进行UPGMA聚类分析,可将16份榧树种质分为3个类群,其中第一个类群由‘东白珠’和‘细珍珠’组成;第二个类群包括‘象牙榧’、‘龙凤细榧’、‘新昌1号’、‘东榧1号’、‘东榧4号’、‘磐安20301’、‘磐安20302’、‘磐安20314’、‘磐安长榧’、‘立勤细榧’、‘诸优2号’、‘诸优3号’、‘诸优4号’;‘早缘榧’单独归为一个类群。研究表明,利用ISSR标记可有效揭示榧树种质的遗传多样性和亲缘关系。研究结果可为榧树种质鉴定及杂交育种提供理论依据。

基于SRAP标记分析的雄性榧树及榧树物种的遗传多样性

雌雄异株天然杂交的榧树(Torreya grandis Fort. ex Lindl)存在着丰富的自然变异,具有巨大的选育潜力,自然界也不乏与榧树优良自然变异类型经无性繁殖培育而成的栽培类型香榧(T. grandis‘Merrilli’)相媲美的优良种质。但由于历史的原因及香榧产业的发展,榧树的遗传多样性受到了一定的影响。本研究在已有雌性榧树研究的基础上,采用SRAP标记对雌性榧树相同采样地的雄性榧树居群进行分析,并整合雌雄榧树居群的标记分析结果,研究了榧树物种水平的遗传多样性。结果表明,雄性榧树居群平均PPL为63.67%,等位基因数(Na)为1.636 7,有效等位基因数(Ne)为1.381 3,Nei's基因多样性(H)为0.221 8,Shannon信息指数(I)为0.331 1,说明雄性榧树存在较为丰富的遗传多样性,且变异(81.48%)主要存在于居群内个体间;与雌性榧树遗传参数相比,雄性榧树的相关遗传参数均不如雌株;就物种水平而言,榧树丰富的遗传多样性来源于雄、雌榧树共同的作用。基于研究结果提出要注重保护榧树尤其是雄性榧树的遗传多样性,同时建议基于个体的优良表现开展优株选择。

香榧皇菊复合经营技术及效益评价

为了提高香榧(Torreya grandis Merrillii)幼林土地利用率,增加前期经济收入,解决幼林香榧遮荫问题,在香榧幼林基地内套种皇菊开展复合经营试验,统计分析复合经营的经济效益,观测复合经营对香榧生长的影响,监测复合经营对土壤的影响。结果表明,香榧皇菊复合经营试验样地每年可增收2050元/667 m^2,可节省香榧各项管理费用1050元/667 m^2;皇菊对香榧树盘基部形成的覆盖遮荫,可降低地表温度,减轻夏季高温对香榧叶片的灼伤程度;实施复合经营后土壤有机质、全氮、有效磷、速效钾的含量得到显著提高。复合经营不但增加前期经济收入,节省香榧管理支出,提供香榧遮荫环境,同时优化基地土壤,促进香榧生长。