This study presents a chromosome-level, near-complete genome assembly of Thalia dealbata (Marantaceae), a typical emergent wetland plant with high ornamental and environmental value. Based on 36.99 Gb PacBio HiFi reads and 39.44 Gb Hi-C reads, we obtained a 255.05 Mb assembly, of which 251.92 Mb (98.77%) were anchored into eight pseudo-chromosomes. Five pseudo-chromosomes were completely assembled, and the other three had one to two gaps. The final assembly had a high contig N50 value (29.80 Mb) and benchmarking universal single-copy orthologs (BUSCO) recovery score (97.52%). The T. dealbata genome had 100.35 Mb repeat sequences, 24,780 protein-coding genes, and 13,679 non-coding RNAs. Phylogenetic analysis revealed that T. dealbata was closest to Zingiber officinale, whose divergence time was approximately 55.41 million years ago. In addition, 48 and 52 significantly expanded and contracted gene families were identified within the T. dealbata genome. Moreover, 309 gene families were specific to T. dealbata, and 1,017 genes were positively selected. The T. dealbata genome reported in this study provides a valuable genomic resource for further research on wetland plant adaptation and the genome evolution dynamics. This genome is also beneficial for the comparative genomics of Zingiberales species and flowering plants.

'德钦'紫花苜蓿(Medicago sativa L.'Deqin',以下简称'德钦'苜蓿)是一种优良的地方品种,具有特异耐旱性、耐热性和耐酸铝性.本研究利用Illumina第二代高通量测序技术对其叶绿体全基因组进行测序(NCBI登录号:MN218692),并对其结构及特征进行分析.结果显示:'德钦'苜蓿叶绿体基因组含有一个反向重复区,属于IR缺失型;总长为125 470 bp,共有110个基因,其中蛋白质编码基因76个、tRNA 30个和rRNA 4个,缺失3个基因(rpsl6,rpl22和infA),总GC含量为33.9％;相对同义密码子使用度显示,'德钦'苜蓿70.74％的密码子使用度＞1,偏好以A和T结尾;共鉴定出115个SSRs位点,其中clpP基因鉴定出与紫花苜蓿不同SSRs位点;最大似然树结果显示'德钦'苜蓿与紫花苜蓿聚在一起,支持率为75％.研究结果将对苜蓿属叶绿体基因组工程研究及'德钦'苜蓿特异基因的进一步鉴定利用提供一定的参考价值.

Aluminum (Al) toxicity is one of the factors limiting alfalfa production on acid soils. This study aims to investigate the different mechanisms in growth, Al content, pectin content, pectin methylesterase (PME) and the degree of pectin methyl-esterification (DM) in the two root segments of different ecotypes alfalfa during the time of Al stress. It was found interesting that lower root elongation and higher Al content were observed in the Al-sensitive ecotype compared to the Al-resistant ecotype of alfalfa. The Al accumulation increased with the increased of stress time. Meanwhile, the pectin and PME activity of cell wall significantly increased. While DM in Al-sensitive ecotype decreased, more free pectin acid residues on the cell wall of Al-sensitive ecotype. The Al content was higher in 0-5 mm root segments and the cell wall for both materials. The increase in pectin content and PME activity along with the decrease in DM in this segment could determine the alfalfa sensitivity to Al more effectively. The correlation analysis showed that there was a relationship between Al content, pectin content, PME activity of cell wall and DM. The different temporal dynamics and spatial differences caused the increase of Al content, pectin content and cell wall PME activity, changes of DM under Al toxicity cooperates to determine the difference of Al resistance that confers different ecotypes of alfalfa.

为探讨木豆[Cajanus cajan(L.)Millsp.]响应低温胁迫的机制,本研究以1份耐低温(MD)和1份低温敏感(QZ)木豆为试验材料,经4℃低温胁迫处理后进行RNA-seq测序分析,结果表明:2份木豆RNA-seq获得了丰富的转录本信息,对转录因子和差异表达基因的基因功能进行注释.木豆响应响应低温胁迫的转录因子主要包括MYB,AP2-EREBP等;在两份材料中,GO分析发现DEGs注释在细胞组成中"膜"和生物学过程中"细胞过程",KEGG分析均显著富集在"核糖体"通路中,而MD中还显著富集在植物激素信号转导、昼夜节律-植物等通路.通过两份材料对比,在MD材料中发现特有与耐低温相关的150个DEGs,主要为α-1,4-葡萄糖苷酶,参与碳水化合物、脂质代谢等途径.还筛选37个与耐寒相关重要差异表达基因和14条通路,并对10个DEGs进行qRT-PCR验证.本文从分子水平阐述了木豆低温胁迫下的响应机制,为未来木豆的抗寒育种奠定了理论基础.

为探讨核酮糖-1,5-二磷酸羧化酶(Rubisco)和Rubisco活化酶(Rubisco activase,RCA)活性变化及其基因表达,本研究以云南野生紫花苜蓿(Medicago sativa)和'阿尔冈金'紫花苜蓿为材料,测定其在干旱和高温条件下植株叶片Rubisco和RCA酶活性,并采用RT-qPCR分析Rubisco大亚基(rbcL)和Rubisco活化酶基因(rca)对干热胁迫的响应.结果表明随干热胁迫时间的延长,野生紫花苜蓿的Rubisco酶活性总体高于'阿尔冈金',且野生紫花苜蓿中的RCA酶活性对干热胁迫的响应时间较'阿尔冈金'晚.rbcL基因和rca基因表达量受干热胁迫影响起初显著上升,而后随干热胁迫时间的延长持续降低,但野生紫花苜蓿的基因表达水平总体高于'阿尔冈金'.2种酶活性与其基因表达之间的相关性均不显著,而rbc L和rac基因之间的表达量均呈显著正相关.

Medicago sativa 'Deqin' is an excellent alfalfa landrace with strong drought and heat resistant which can grow and propagate very well in Deqin, a xerothermic valley of Jinsha River, China. In this study, the complete chloroplast genome of M. sativa 'Deqin' was assembled. The complete chloroplast genome of M. sativa 'Deqin' represents a typical circular with 125,470 bp in length, containing one inverted repeat (IR) region. Gene prediction revealed 110 genes encoding 76 proteins, 30 transfer RNAs, and four ribosome RNAs. Three genes (rps16, rpl22 and infA) are absent. The overall GC content is 33.9%. The phylogenetic analysis revealed that M. sativa 'Deqin' belonged to the IR lacking clade, and was closely related to M. sativa with a 100% bootstrap support.

无人机遥感信息技术广泛应用于地表类型分类及监测.本研究均匀提取分布于研究区内的982个分类样本点,利用包括Sentinel-1/2 (S1/2)数据集、S2数据集计算获得的植被指数(Vegetation index,Ⅵ)数据集和数字高程模型(Digital Elevation Model,DEM)数据集的遥感影像资料,借助随机森林分类模型完成研究区地表类型分类.结果 显示:4种数据集组合(S2数据集、S2&Ⅵ数据集、S2&Ⅵ&DEM数据集,以及4个S2波段b3&b2&b4&b6组成的数据集)的制图总体精度(Overall Ac-curacy,OA)和Kappa系数精度都在75％和65％以上.此外,在不考虑位于边缘的样本点(即混合像元)后,分类制图结果具有更好的鲁棒,3种分类精度最高的数据集(S2数据集、S2&Ⅵ数据集和S2&Ⅵ&DEM数据集)OA和Kappa系数精度都提高至85％和79％以上.特别是kappa系数的精度更优,提高了近15％.本文研究结果为喀斯特地区的地表类型制图提供了准确而有效的技术手段.

木豆是世界第六大食用豆类,用途非常广泛.木豆遗传多样性非常丰富,植物种质资源特性与其抗逆性密切相关.本综述重点介绍国内外木豆种质资源遗传多样性、抗逆生理生化指标及机制研究进展,同时对木豆产业化研究提出展望,为后期开展木豆抗逆研究及抗逆育种提供参考依据.

Cymbidium tortisepalum is a primary orchid species in Yunnan Province, China, and has an extremely high ornamental and economic value. To reveal the levels and distribution of genetic variation and structure of wild C. tortisepalum resources, sequence variations of six chloroplast DNA intergenic spacers (psbM-trnD, trnV-trnA, accD-psal, rrn23, trnk-rps16, and ycf1) were analyzed in 404 wild individuals from 28 populations in the three river area in Yunnan Province, China. The results showed that the six chloroplast DNA sequences were aligned with 61 polymorphic sites, including 50 indels and 11 haplotypes in 404 individuals, which revealed a low level of genetic diversity (total genetic diversity = 0.240, and the average value of nucleotide diversity = 0.00024). In addition, a fairly low genetic differentiation [coefficients for genetic differentiation among populations (G(ST)) = 0.099, number of substitution (N-ST) = 0.081] was found among the studied populations, and N-ST value was less than G(ST), which indicated that no significant phylogeographic structure existed in those populations. Furthermore, analysis of molecular variance revealed that great genetic variance (91%) came from individuals within the populations, which indicated that there was no clear genetic differentiation among populations. On the basis of these findings, a conservation plan was proposed to sample or preserve fewer populations but with more individuals from each population.

利用基于气相色谱质谱联用技术的代谢组学方法,研究0、50mmol/L、100mmol/L、200mmol/L、300mmol/L、400mmol/L NaCl胁迫下多年生黑麦草代谢组分的变化,共检出391个色谱峰,利用Mann-Whitney和KruskabWallis检验获得114种显著变化代谢物(P＜0.01),采用s-plot分析获得17个靶标代谢物,用MetaboAnalyst4.0对17种代谢靶标进行通路富集分析获得8条显著变化的代谢通路(P＜0.05),分别是淀粉和蔗糖代谢、甘氨酸丝氨酸和苏氨酸代谢、丙氨酸天冬氨酸谷氨酸代谢、氨酰tRNA生物合成、半乳糖代谢、乙醛酸和二羧酸代谢、氰基氨基酸代谢、光合碳循环.随着NaCl浓度升高,脯氨酸含量升高,抗坏血酸和水杨酸含量随之升高然后到400mmol/L浓度下降,吲哚乙酸在50mmol/L NaCl胁迫时升高,之后下降,乙烯生物合成前体物质1-氨基环丙烷基-1-羧酸则一直呈累积趋势.相对含水量和丙二醛含量在50mmol/L NaCl胁迫下分别升高和下降,而100～400mmol/L NaCl胁迫处理相对含水量逐渐下降,丙二醛含量逐渐升高.

Climate changes severely influence photosynthetic activity of plants. Studies on the combined effect of drought and heat stress on photosynthesis, pigments, and xanthophyll cycle particularly in alfalfa (Medicago sativa L.) are limited. Thus, this study investigated the combined effects of drought and heat stress in two alfalfa varieties (`Deqin' and `Algonguin'). Results revealed that the values of the net photosynthetic rate demonstrated a significantly decreasing tendency under stresses. The effect of stresses on ribulose 1,5-bisphosphate carboxylase activity in both varieties showed a trend of first declining and then rising. Meanwhile, phosphoenolpyruvate carboxylase activity showed an increasing tendency. The intensification of stresses led to reduced photochemical efficiency and increased capability of thermal dissipation. A linear correlation was found between nonphotochemical quenching and xanthophyll cycle components. Thus, the change in carotenoids demonstrated an important role in photoprotection, the xanthophyll cycle was the main way of dissipation of excess energy under stress conditions in alfalfa.

[目的]高寒坝区生态环境脆弱,过度放牧及开垦导致土壤碳氮储量下降,掌握土壤养分特征及变化规律,制定生态恢复措施,对生物多样性的保护具有重要意义.[方法]本研究以迪庆州高寒坝区农田、灌丛地、放牧草地和封育草地4种土地土壤为研究对象,研究土壤有机碳、碱解氮、全氮的垂直分布特征及SOC与TN间相互关系,以期为中甸高寒坝区的生态系统恢复和土地利用方式提供参考依据.[结果](1)同一类型土壤不同土层SOC含量随深度增加呈递减趋势;不同处理0～30 cm土层SOC含量以农田最高,30～40 cm土层以灌丛地最高,差异显著(P<0.05);(2)农田及灌丛地10～20 cm土层AHN含量最高,总体随土层深度增加呈先上升后下降的趋势;放牧地0～10 cm土层AHN含量最高,封育草地0～10 cm、10～20 cm土层AHN含量相同,10～40 cm土层AHN含量随土层深度增加呈下降趋势;对比相同土层,草地的AHN含量较高;(3)TN含量在各处理下均随深度的增加显著下降(P<0.05),0～20 cm土层以农田含量最高,而20～30 cm和30～40 cmTN含量最高的分别是放牧地和灌丛地(P<0.05);(4)SOC、TN相关性为封育草地>灌木地>放牧草地>农田.[结论]人为因素对于土壤碳氮储量影响较大,建议可通过合理施肥、灌溉,减少农田土壤有效碳、氮的流失,种植灌木固持土壤营养元素,轮牧、封育以提高放牧草地土壤营养元素间相关性保证土壤养分的收支平衡.

The effects of elevated aluminium (Al) concentrations on parameters indicating Al toxicity and Al detoxification were evaluated in two alfalfa populations from different acidic soil environment. Plants were grown in nutrient solutions at pH 4.5, 5.5 and 6.0, with different levels of Al contamination for 30 days. Shoot heights and root activity were significantly decreased in the Al treatment while free proline concentration was significantly increased. Furthermore, citric acid and oxalic acid concentrations tend to increase with increasing Al concentration. Different responses were also observed between the two populations. Shoot height, free proline concentration and root activity were significantly higher for alfalfa plants collected from an acidic soil environment. These plants also exhibited higher concentrations of citric and oxalic acids when exposed to 100 mu M Al at pH 4.5. Overall, the results indicate that alfalfa plants grown on acidic soils might develop mechanisms to be less affected by high Al concentration.

采用溶液培养的方法对前期筛选的两份云南逸生紫花苜蓿(Medicagosativa)No.12(耐受基因型)和No.21(敏感基因型)材料进行铝处理,研究铝对不同耐铝基因型苜蓿材料根尖及细胞壁氧化酶活性的影响.结果表明:随铝胁迫时间的延长,紫花苜蓿根系生长受抑制程度加剧,根尖及细胞壁铝含量增加,其中细胞壁铝含量积累较根尖更为显著;且敏感型苜蓿材料根系伸长受抑程度更为明显,其根尖及细胞壁铝积累量均高于耐受型材料;铝胁迫下,两份材料根尖过氧化物酶(POD)活性和超氧化物歧化酶(SOD)活性均呈先上升后下降的变化趋势,而细胞壁POD、SOD活性均呈显著增加趋势,过氧化氢(H2O2)含量也呈现类似的趋势,且敏感基因型苜蓿材料氧化酶活性的升高及H2O2累积更为显著.细胞壁是苜蓿结合铝离子的重要靶点,随着铝毒害的加深,敏感型苜蓿材料细胞壁氧化酶活性的升高和H2O2积累显著,引起根系木质化和细胞壁氧化交联,根尖细胞壁刚性提高而伸展能力降低,这是敏感基因型紫花苜蓿材料根系伸长受伤害程度更高的重要原因,也是紫花苜蓿细胞壁调控铝毒的重要机制之一.

土壤酸化已经在全球范围内引起高度重视,铝毒被认为是酸性土壤(pH＜6.5)限制植物生长的重要因素,本文概述了土壤中铝的化学形态、铝对植物的毒害、草本植物耐酸铝性研究进展及草本植物的耐铝机制,以期为各类草本植物耐铝毒机制的深入研究提供参考.

To identify the important pathways related to the drought-resistant metabolic mechanism of ryegrass, the main metabolites of blue heaven were detected and studied by gas chromatography-mass spectrometry (GC-MS) under natural drought stress. Using partial least squares discrimination analysis and principal components analysis could completely distinguish between the control and drought stress group; furthermore, there were 19 metabolomic markers obtained by the s-plot analysis. Abundance of 10 biomarkers decreased, namely itaconic acid, taurine, sucrose, glucose, lysine, isoleucine, tyrosine, asparagine, myo-inositol, 1-aminocyclopropane-1-carboxylic acid. Abundance of nine biomarkers increased, namely fructose, phenylalanine, homoserine, 1-hydrogen indole, threonine, phosphate, creatinine, citric acid, malic acid. Enriched pathway analysis by MetaboAnalyst 4.0 obtained nine significant metabolic pathways (P < 0.05), namely Ascorbate and aldarate metabolism; Glycine, serine and threonine metabolism; Alanine, aspartate and glutamate metabolism; Citrate cycle (TCA cycle); Galactose metabolism; Aminoacyl-tRNA biosynthesis; Arginine and proline metabolism; Lysine biosynthesis; Cyanoamino acid metabolism. The nine pathways were associated with drought resistance of ryegrass. The main metabolic pathways of Lolium multiflorum under drought stress were identified through the study, which is of great significance to explore the mechanism of drought resistance metabolism of Lolium multiflorum and would provide reference for further promotion of Lolium multiflorum.

[目的]建立适合紫花苜蓿(Medicago sativa L.)叶片叶黄素循环组分:紫黄质(V)、环氧玉米黄质(A)和玉米黄质(Z)含量测定的方法.[方法]采用高效液相色谱(HPLC)法对紫花苜蓿叶片叶黄素循环的3个组分进行了测定,并对试验方法进行了验证.[结果]V、A和Z三个组分的标准品在3～100 μg/mL范围内均与峰面积呈良好的线性关系,相关系数分别为r=0.999 49、r=0.999 61和r=0.999 60,精密度试验(n=5)的RSD分别为0.96％、0.39％和0.87％,稳定性试验(n=7)的RSD值分别为3.33％、1.42％和1.86％,重现性试验(n=5)的RSD分别为0.48％、3.98％和2.59％,平均回收率(n=3)分别为99.55％、96.04％和94.08％,RSD分别为0.96％、1.38％和0.51％.[结论]HPLC法适于紫花苜蓿叶片叶黄素循环组分V、A和Z含量测定,该方法精密度高、重复性和稳定性好,回收率高.

铝毒是紫花苜蓿(Medicago sativa)在南方酸性土壤地区种植的主要限制性因素之一.筛选能够在酸性富铝化土壤中生长优良的苜蓿材料,对于紫花苜蓿在南方大面积推广具有重要意义.本研究选用27份云南紫花苜蓿为材料,研究100 mg·kg-1浓度铝胁迫处理下供试材料株高、脯氨酸、根系活力以及有机酸含量的变化.结果表明,铝对苜蓿生长具有明显的抑制作用,且不同材料反应敏感性不同.铝对供试苜蓿株高和根系活力有明显抑制作用;铝处理下苜蓿叶片中游离脯氨酸、有机酸含量显著积累(P<0.05),所有供试材料的相对脯氨酸含量均大于100％,但不同材料相对有机酸含量表现差异较大.采用聚类分析及隶属函数法综合评价供试苜蓿材料的耐受性,以15,12,14,13号材料表现较优,可用于选育适应酸性富铝化土壤的苜蓿品种.

普通生态学是一门研究生物有机体与其周围环境相互关系的科学.本文以云南农业大学为例,对讲授教师、 授课对象、 课堂形式、 实验课、 成绩考核形式、 学校管理评估及提高学生兴趣等方面进行探讨,分析普通生态学教学改革的具体措施及内容,努力创建利于学生学习的课堂氛围与实践教学相结合的组织形式和管理体制,构建多元化的实践教学体系,为生态教学开辟新途径.

为评估不同品种紫花苜蓿氮代谢对Cd的耐性并筛选可靠评价指标,以20个紫花苜蓿(Medicago sativa L.)品种为植物材料,以0、50 mg·kg-1两个Cd处理浓度为土壤条件,开展温室盆栽试验.测定各品种的株高、生物量、全氮含量、硝态氮含量、脯氨酸含量、游离氨基酸含量、可溶性蛋白含量及氮代谢关键酶(硝酸还原酶、谷氨酰胺合成酶、谷氨酸合酶和谷氨酸脱氢酶)活性指标,计算Cd胁迫后各指标的变化率;分析各指标变化率之间的相关性,并利用主成分分析法和隶属函数法计算各品种的综合评价值(D),建立D值的回归模型并筛选Cd耐性的评价指标.结果显示,Cd胁迫后,11个指标在不同品种中的变化率各不相同,其中增幅最大的指标是品种"WL525HQ"中的硝态氮含量(122.24％),降幅最大的指标则是品种"WL525HQ"中的硝酸还原酶活性(-83.00％).在株高、生物量、全氮含量、可溶性蛋白含量、脯氨酸含量、硝酸还原酶活性、谷氨酰胺合成酶活性和谷氨酸合酶活性8个指标之间,呈两两显著正相关关系(P<0.05或P<0.01).20个紫花苜蓿品种中,"巨人"的D值最大(0.89),其氮代谢具有最强的耐Cd性,而"三得利"的D值最小(0.04),其氮代谢Cd耐性最弱.多元线性回归分析筛选出株高、谷氨酰胺合成酶、谷氨酸脱氢酶、硝态氮、硝酸还原酶和生物量6个单项指标作为评价紫花苜蓿氮代谢Cd耐性的主要指标,为紫花苜蓿Cd耐性品种的筛选与鉴定提供依据和数学模型.