Natural variations in flavonoids and triterpenoids of Cyclocarya paliurus leaves

Cyclocarya paliurus is widely distributed in subtropical areas of China.Secondary metabolites in the leaves,including flavonoids and triterpenoids,provide protection against diseases such as hyperlipidemia,diabetes,hypertension,and hypoimmunity.In this study,343 C.paliurus leaves were collected from 32 distinct populations covering most of the main distribution,to deduce the response of flavonoids and triterpenoids to seven environmental factors.Principal component analysis was performed using seven flavonoid and six triterpenoid compounds.The results show that altitude,latitude,and longitude significantly contributed to variations in total flavonoid and triterpenoid contents.In addition,the interaction of these metabolites was extensively correlated with environment changes,and therefore should be considered during selection and cultivation.

Genetic diversity and association analyses of fruit traits with microsatellite ISSRs in Sapindus

Sapindus mukorossi Gaertn. and S. delavayi Franchet are among the most valuable species in the genus Sapindus for their commercially exploitable plant oils and chemicals. However, few studies have addressed genetic variation and improvement for either species. We evaluated the genetic diversity of germplasm from selected plus trees within a wide region and established the relationship between fruit traits and molecular markers. An association analysis based on inter-simple sequence repeats(ISSRs)provided a genetic basis for studies of fruit traits. A total of 247 loci were detected by scanning 61 trees of S. mukorossi and S. delavayi using 16 ISSR markers. Genetic diversity parameters were estimated for selected superior trees(or germplasm) and S. mukorossi and S. delavayi were categorized into two main groups, as well as into four groups within S. mukorossi. An association analysis between the ISSR markers and 14 fruit traits used the TASSEL MLM model. A genetic structure analysis differentiated S.mukorossi and S. delavayi. Eighteen ISSR loci associated with 13 fruit traits(P<0.005) were identified, with 13, 1,and 4 loci associated with seed oil production, fruit saponin production, and fruit quality, respectively. Using this information, a core collection was selected with adequate genetic diversity and good seed oil characters. Our results demonstrate the feasibility of effectively estimating fruit trait associations in Sapindus using ISSR markers, and the method is applicable and valuable for select germplasm conservation. The markers obtained in this study are potentially useful for molecular-assisted breeding of Sapindus spp.

Screening of Sapindus germplasm resources in China based on agro-morphological traits

Sapindus L.species are widely cultivated for biodiesel,biomedical,and biochemical raw materials in southern China.However,yields fuctuate widely due to the lack of high-yielding,high-quality,stable cultivars.Therefore,the objectives of this study were to evaluate three species and one variety among 149 nationwide Sapindus species and screen for elite accessions which would serve as Sapindus breeding materials.Accessions were evaluated on 19 agro-morphological traits by correlation analysis and principal component analysis.These displayed substantial diversity and a broad range of economic traits.In particular,accessions of Sapindus mukorossi and Sapindus rarak had more variation in economic traits than Sapindus delavayi and Sapindus rarak var.velutinus.Increased saponin accumulation may be achieved at the cost of seed oil production.Thirty elite accessions for oil and saponin production,and for comprehensive utilization were screened and accessions no.80,110,and 112 had significant potential to produce high yields.These elite accessions will facilitate the identification of genetic determinants of valuable traits and the effective utilization of trait variability in Sapindus breeding.

Whole-genome Duplication Reshaped Adaptive Evolution in A Relict Plant Species,Cyclocarya paliurus

Cyclocarya paliurus is a relict plant species that survived the last glacial period and shows a population expansion recently.Its leaves have been traditionally used to treat obesity and diabetes with the well-known active ingredient cyclocaric acid B.Here,we presented three C.paliurus genomes from two diploids with different flower morphs and one haplotype-resolved tetraploid assembly.Comparative genomic analysis revealed two rounds of recent whole-genome duplication events and identified 691 genes with dosage effects that likely contribute to adaptive evolution through enhanced photosynthesis and increased accumulation of triterpenoids.Resequencing analysis of 45 C.paliurus individuals uncovered two bottlenecks,consistent with the known events of environmental changes,and many selectively swept genes involved in critical biological functions,including plant defense and secondary metabolite biosynthesis.We also proposed the biosynthesis pathway of cyclocaric acid B based on multi-omics data and identified key genes,in particular gibberellinrelated genes,associated with the heterodichogamy in C.paliurus species.Our study sheds light on evolutionary history of C.paliurus and provides genomic resources to study the medicinal herbs.