Elevational and temporal patterns of pollination success in distylous and homostylous buckwheats(Fagopyrum)in the Hengduan Mountains

Reproductive strategies of sexually dimorphic plants vary in response to the environment.Here,we ask whether the sexual systems of Fagopyrum species(i.e.,selfing homostylous and out-crossing distylous)represent distinct adaptive strategies to increase reproductive success in changing alpine environments.To answer this question,we determined how spatial and temporal factors(e.g.,elevation and peak flowering time)affect reproductive success(i.e.,stigmatic pollen load)in nine wild Fagopyrum species(seven distylous and two homostylous)among 28 populations along an elevation gradient of 1299-3315 m in the Hengduan Mountains,southwestern China.We also observed pollinators and conducted hundreds of hand pollinations to investigate inter/intra-morph compatibility,self-compatibility and pollen limitation in four Fagopyrum species(two distylous and two homostylous).We found that Fagopyrum species at higher elevation generally had bigger flowers and more stigmatic pollen loads;lateflowering individuals had smaller flowers and lower pollen deposition.Stigmatic pollen deposition was more variable in distylous species than in homostylous species.Although seed set was not pollenlimited in all species,we found that fruit set was much lower in distylous species,which rely on frequent pollinator visits,than in homostylous species capable of autonomous self-pollination.Our findings that pollination success increases at high elevations and decreases during the flowering season suggest that distylous and homostylous species have spatially and temporally distinct reproductive strategies related to environment-dependent pollinator activity.

五个中国荞麦(Fagopyrum)种的核型分析

用去壁低渗法对甜荞 ( Fagopyrum esculentum)、苦荞 ( F.tataricum)、左贡野荞 ( F.zuogongense Q.F.Chen) ,大野荞 ( F.megaspartanium Q.F.Chen)及毛野荞 ( F.pilus Q.F.Chen)等大粒组荞麦种的根尖和茎尖有丝分裂染色体进行了观察 ,并对其茎尖有丝分裂染色体的核型进行了比较分析。结果表明 :这 5种荞麦在核型上类似 ,都有 2对随体染色体 ,而且都为对称核型。但它们彼此有一定的差异。甜荞、苦荞、大野荞、毛野荞及左贡野荞的核型公式分别为 1 2 m+4m( SAT)、1 2 m+4sm( SAT)、8m+4sm+4m( SAT)、1 2 m+2 m( SAT) +2 sm( SAT)及 2 4 m+4sm+4m( SAT)。

Comparison of Two Methods for Measuring Flavonoid Content of Fagopyrum megaspartanium Leaves

[Objective] The aim was to study the flavonoid content of Fagopyrum megaspartanium leaves by water bath and ultrasonic extractions.[Method] By using water bath extraction and ultrasonic extraction,the total flavonoid content in buckwheat leaves was measured with UV spectrophotometer.[Result] The optimum wavelength for determination of the content of flavonoid extracted from buckwheat leaves was 420 nm;the content of total flavonoid extracted by ultrasonic extraction and water bath extraction from buckwheat were 5.26% and 5.40% respectively;and the average total flavonoid content by water bath extraction was significantly higher than that by ultrasonic extraction.[Conclusion] The result is significant for the improvement of flavonoid content measurement of buckwheat.

Effects of Light Intensity on Growth, Development and Formation on Fagopyrum cymosum

Effects of light intensity on growth, development and formation on Fagopy- rum cymosum were explored with natural light intensities at 100%（A）, 85.2%（B）, 75.8%（C） and 59.7%（D）. The results showed that the decline of light intensity re- duced nutrient growth period, so that plant growth stage entered in advance and extended, which indicated that the decline of light intensity would lower leaf number and area, the number of twigs from the stem, as well as photosynthate. Further- more, the reduction degree increased upon light intensity decrease degree, and the proper shading improved stem height and leaf area enhanced before growth term.

Principal Component Analysis and Cluster Analysis of Fagopyrum tataricum Varieties(Lines)

In order to reveal the genetic differences and agronomic traits of Fagopy-rum tataricum_ varieties （lines） intuitively, explore good resources and avoid the blindness of parent selection during the breeding process, six primary agronomic traits of 45 F. tataricum_ varieties （lines） that came from the eleven buckwheat breeding departments across the country were analyzed with principal component analysis and cluster analysis. The results of principal component analysis showed that the six agronomic traits could be simplified into three principal components, and the cumulative contribution rate reached 83%. The results of cluster analysis showed that the 45 F. tataricum varieties （lines） were classified into four groups：high stalk, medium yield and smal grain type, medium stalk, high yield and large grain type, medium stalk, low yield and smal grain type and high stalk, medium yield and medium grain type. Among them, performance of comprehensive trait of the second type was better than that of the other types. Thus, the F. tataricum_va-rieties （lines） that were classified into the second type could be considered as good varieties （lines） or breeding materials. The genetic differences among F. tataricum_varieties （lines） had no necessary correlations with origin and geographical distance. ln addition to complementary traits and geographical distance, genetic distances （dif-ferent populations） should be taken into consideration during parent selection in cross breeding.

Optimization of the Conditions of SRAP Molecular Marker Used in Analysis of Fagopyrum tataricum

[Objective] The aim was to investigate the optimal conditions of SRAP molecular marker used in the analysis on Fagopyrum tataricum（L.）Gaertn.[Method]SRAP-PCR amplification system on Fagopyrum tataricum was optimized by interactive orthogonal design L27（313）in 5 elements（Mg2＋,dNTP,Taq DNA polymerase,template DNA and primer）at 3 levels.And the non-denaturing and denaturing PAGE detection methods were compared.The comparative test of DYCZ-24F and DYCZ-20C electrophoresis operating systems was carried out.[Result]The effects of four single-factor（Mg2＋,dNTP,Taq DNA polymerase and primer）and two interactions（Mg2＋×dNTP,Mg2＋×Taq DNA polymerase）on tartary buckwheat SRAP-PCR were significant.An optimal reaction system was established containing 1.5 mmol/L Mg2＋,0.2 mmol/L dNTP,1.5 u Taq DNA polymerase,40 ng DNA,0.25 μmol/L primer and 2 μl 10×buffer.Seven samples of tartary buckwheat were amplified using this system,and electrophoresis results showed clear bands,high level of polymorphism and good reproducibility.The PCR products were tested by denaturing and non-denaturing PAGE,and the results showed that the non-denaturing PAGE,DYCZ-24F operating system was more suitable for SRAP analysis.[Conclusion]This study established a foundation for the construction of SRAP genetic map of tartary buckwheat.

Phenolic Profiles and Antioxidant Activity of Buckwheat (Fagopyrum esculentum Mench and Fagopyrum tartaricum L. Gaerth) Hulls, Brans and Flours

The extracts from hulls, brans and flours of Fagopyrum esculentum M6ench （FEM, three varieties） and Fagopyrum tartaricum L. Gaerth （FTG, seven varieties） were screened for free and bound phenolic content or total phenolic content （TPC）, as well as 1,1 diphenyl-2-picryl hydrazyl （DPPH） free radical scavenging activity and reducing power. Free phenolics were predominant in buckwheat hulls, brans and flours. FEM hulls extract exhibited the highest reducing power and DPPH free radical scavenging activity with the average ECs0 84.54 μg mL^-1 and IC50 11.54 μg mL^-1 respectively, FTG brans extract had the highest average TPC （24.87 mg GAE g^-1 DW）, and FEM flours extract showed the lowest TPC, reducing power and radical scavenging activity. Furthermore, the correlations among TPC, DPPH free radical scavenging activity and reducing power of all the samples were investigated. The rank correlation coefficient （rs） between reducing power and DPPH free radical scavenging activity of buckwheat hulls, between TPC and DPPH free radical scavenging activity of buckwheat flours were 0.76 and 0.79, respectively （P〈0.05）. However, there is no significant correlation between the remaining indexes of hulls and flours, as well as the ten buckwheat brans. This result indicated that some non-phenolic compounds also contributed to the total antioxidant activity in hulls, brans and flours of buckwheats. This study demonstrated that buckwheat hulls and brans, rather than flours, are good source of antioxidants.

Cloning and Analysis of a Chalone Synthase Gene from Fagopyrum tataricum

[Objective] This study aimed to clone a full-length CHS gene from buck- wheat. [Method] With total RNA extracted from buckwheat as the template, CHS cD- NA sequence was cloned from buckwheat by using RACE technology and CODEHOP primer design method, the full length gene was obtained by primers which were de- signed for amplification of full-length gene sequence with buckwheat DNA template. Clustalxl.81 and MEGA4 software were used for sequence analysis and construction of phylogenetic tree; NCBI Blastn and Biastp programs were applied for homology analysis of nucleic acid and protein. [Result] Bioinformatics analysis showed that the full length of this gene is 1 906 bp, containing a 463 bp intron sequence and a 1 188 bp coding region, encoding 395 amino acids. Blastn sequence alignment revealed that the CHS gene sequence obtained in this study shared 86% homology with the CHS gene of closely related species. [Conclusion] This study laid the foundation to clarify molecular basis of the synthesis of buckwheat bioflavanoids and explore an effective way to improve the content of buckwheat bioflavanoids.

A phenolic glycoside from Fagopyrum dibotrys (D.Don) Hara

A new phenolic constituent along with five known compounds were isolated from Fagopyrum dibotrys (D.Don) Hara. The new compound was characterized as 1,3-dimethoxy-2-O-β-xylo-pyranosyl-5-O-β-glucopyranosyl-benzene, by spectroscopic analysis and enzymatic hydrolysis.

Effects of Heat Treatment on Flavonoids Content and Antioxidant Capacity of Buckwheat (Fagopyrum tataricum Gaert) Flour Ethanolic Extracts

The chemical composition, total flavonoids and antioxidant capacity of 50% ethanolic extracts from raw and cooked buckwheat flour from southwest of China were determined. The heat treatment used to gelatinize the flour starch significantly reduced the total flavonoids in the extract from 83.52 to 67.36 mg 100 g 1 of dry matter in the raw and cooked flour, respectively. The antioxidant capacity of the extracts was evaluated using autooxidation in a β carotene linoleate model system (AA or AAC), DPPH radical scavenging assay (IP) and oxygen radical absorbance capacity (ORAC) assay. Values for raw buckwheat flour extract were 97.84, 874.31, 76.45 and 94.92% for AA, AAC, ORAC and IP, respectively, while values in cooked buckwheat flour were 86.14, 842.88, 63.93 and 94.74% for AA, AAC, ORAC and IP, respectively. Values before cooked and raw buckwheat flour extracts were significantly different ( P <0.05) for AA, AAC, and ORAC.

STUDIES ON MUTAGENICITY.ANTI-MUTATION AND TERATOGENY OF FAGOPYRUM CYMOSUM(TREV)MEISN

Fagopyrum Cymosum(Trev)Meisn is a tannin compound fromchinese herbs,and is used for treatment of pulmonaryabscess,anti-tumor test showed that the drug inhibit-ed pulmonary carcinoma in Lewis,cervical carinoma,

Effect of Planting Density on Physiological Indexes, Agronomic Traits and Yield of Buckwheat ( Fagopyrum esculentum Moench.)

Ningqiao 1 was selected as the material to study the effects of planting density on physiological indices,agronomic traits and yield of buckwheat.The results showed that high density resulted in decreases of chlorophyll content,soluble protein content and activity of SOD,POD and CAT,and acceleration of MDA accumulation under drought conditions.Low density could effectively improve the grain number per plant,grain weight per plant,1000-grain weight and yield in drought conditions.

内蒙古呼包地区甜荞种质资源农艺性状鉴定与评价

引进甜荞(Fagopyrum esculentum Moench.)种质资源77份,进行农艺性状的田间鉴定,以期筛选出适宜内蒙古呼包地区种植的优异种质资源。结果表明,遗传性变异度以产量和单株粒重最大,变异系数分别为37.1%、38.5%,一级分枝数、单株粒数、第一侧枝长、茎壁厚、株高的变异系数较大,分别为36.6%、33.9%、32.4%、29.4%、21.9%,表明这些性状有丰富的遗传变异;通过对12个农艺性状的聚类分析表明,77份甜荞品种可分为3类,包括矮秆型21份、大粒高产型34份、高秆抗倒型22份;与产量显著相关的性状为单株粒重、千粒重、单株粒数(P<0.01)。综合来看,筛选出适于内蒙古呼包地区种植的兼具矮秆、高产、抗倒性状的优异甜荞种质资源9份。

Do Aqueous Extracts from Buckwheat Compromise Seed Germination and Initial Development of Bidens pilosa and Euphorbia heterophylla?

Fagopyrum esculentum Moench (buckwheat) is a dicot species from the Polygonaceae family used as a cover crop in agricultural systems featured with a remarkable allelopathic potential for weed control, helping herbicide-resistance management and promoting substantial reductions in herbicide applications. The aim of this research was to examine the allelopathic potential of aqueous extracts from seeds and aerial part of buckwheat on seed germination and initial development of Bidens pilosa and Euphorbia heterophylla. Bioassay experiments were conducted under a completely randomized experimental design with four replications, containing 50 seeds each. Both weed seed species were harvested in a soybean field, and seed viability was previously assessed. Seeds were exposed to four concentrations (0, 25, 50, and 100%) from extracts of seeds (ES) and aerial part (EAP) of buckwheat. Germination speed index (GSI) in B. pilosa and E. heterophylla was daily evaluated throughout 14 and 16 days, respectively, whereas percentage of germination, abnormal seedlings, as well as non-germinated seeds, root (RL) and aerial part length (APL), and total dry matter (TDM) were rated at final germination test. EAP reduced the GSI, especially under the 100% concentration. Germination percentage was lower and abnormal seedlings increased for both weed species when seeds were exposed to EAP concentrations greater than 25%. However, ES did not impinge upon E. heterophylla germination. EAP and ES reduced the APL, RL, and TDM for concentrations greater than 50%, except for ES which did not affect E. heterophylla development. Both extracts from buckwheat have a high capacity to inhibit germination and compromise seedling development, culminating in such a potential alternative for B. pilosa and E. heterophylla management in agricultural systems.

金荞麦有效成分及含量变化研究

采用HPLC法对金荞麦(Fagopyrum cymosum)的有效成分进行了分析。结果表明,金荞麦含有芦丁、槲皮素和表儿茶素等有效成分,但不同器官的含量差异较大。芦丁含量以花、叶较高,种子居中,茎和根状茎很低。槲皮素含量则以种子最高,花其次,叶、茎和根状茎较低;表儿茶素含量以根状茎最高,花和种子的含量甚微,茎和叶中未见有表儿茶素成分。金荞麦叶中的芦丁含量以及根状茎中的表儿茶素含量在开花结实期达最高峰,以后逐渐降低。

干旱胁迫对甜荞幼苗生理特性的影响

为探究甜荞(Fagopyrum esculentum Moench.)幼苗期对干旱胁迫的应答机制,以甜荞品种‘西农9976’为供试材料,采用不同质量分数(0%、5%、10%和12%)的PEG-6000溶液对荞麦幼苗进行为期5d的干旱胁迫处理,研究了甜荞幼苗期生理特性的动态变化规律。结果表明,随着PEG-6000浓度的增加以及胁迫时间的延长,甜荞幼苗的叶片相对含水量持续显著降低,叶片中的超氧阴离子自由基(O-·2)产生速率和过氧化氢(H2O2)含量总体呈上升趋势;同时,抗氧化酶SOD、POD和CAT的活性均呈现先升高后降低的趋势。此外,干旱胁迫使丙二醛(MDA)含量持续积累并于胁迫第5天达到高峰。研究结果还表明,干旱胁迫下活性氧(ROS)在甜荞幼苗叶片中均有不同程度的累积,轻度胁迫下抗氧化酶类能够对其进行有效的清除,且能维持植株的正常生长;但中度和重度胁迫下超出了抗氧化酶类的清除能力,氧化和抗氧化平衡状态受到破坏,从而导致细胞的膜脂过氧化程度加剧,植株受害严重。

盐胁迫下五个苦荞麦品种的耐盐性比较

以5个不同苦荞麦[Fagopyrum tataricum(L.)Gaertn.]品种为试验材料,在100 mmol/L Na Cl胁迫下测定荞麦种子发芽率、幼苗根系活力、叶片质膜透性和Na+含量等指标,对5个苦荞麦品种种子萌发期和幼苗期的耐盐性进行了比较。结果表明,Na Cl胁迫下川荞1号种子发芽率和幼苗根系活力最高,幼苗叶片质膜透性和Na+含量最低;而川荞2号正好相反。说明在种子萌发期和幼苗期川荞1号的耐盐性最强,川荞2号对盐胁迫最敏感。

甜荞子粒总黄酮提取工艺的优化

为了充分利用荞麦(Fagopyrum esculentum)资源,以内蒙古甜荞子粒为研究对象,利用乙醇提取法提取子粒中总黄酮,并对其工艺进行优化。最终得出荞麦子粒总黄酮提取的最佳工艺条件为乙醇体积分数65%,水浴时间80 min,水浴温度60℃,料液比1∶20(m/V,g∶mL)。

种植密度对荞麦生理指标、农艺性状及产量的影响

以荞麦(Fagopyrum esculentum Moench.)宁荞1号为试验材料,研究了不同种植密度对荞麦生理指标、农艺性状及产量的影响。结果表明,在干旱条件下,高密度加速了荞麦叶片叶绿素的分解和可溶性蛋白质含量的下降,降低了抗氧化酶SOD、POD、CAT的活性及加速了MDA含量的积累。在干旱条件下,低密度处理有利于荞麦单株粒数、单株粒重、千粒重及产量的增加。

荞麦属植物叶片及其愈伤组织中的总黄酮含量

以荞麦属植物叶片为外植体诱导愈伤组织,采用分光光度法测定荞麦属植物叶片及其愈伤组织中总黄酮的含量,筛选出富含总黄酮的品系及其愈伤组织细胞系,为遗传改良培育新品种和工厂化生产芦丁打下基础。