青海草地早熟禾(Poa pratensis L.cv.Qinghai)近几年的研究进展

论述了青海草地早熟禾(Poa pratensis L.cv.Qinghai)野生栽培品种的由来,以及近几年在生物-生态性、恢复生态学、生理生化和高寒草坪方面的工作,提出了青海草地早熟禾目前依然缺乏的研究,指出今后工作的重点,应加强青藏高原育种工作,寻找更多更好的牧草生态型品种。

Stable Transformation of Three Cultivars of Kentucky Bluegrass (Poa pratensis L.) by Particle Bombardment of Mature Seed-Derived Highly Regenerative Callus

High embryogenic calli of three cutivars of Kentucky bluegrass, Md, Bd, and Gm, were induced from mature embryos, and were proliferated on medium K3 and K5. Embryogenic calli were transformed with plamids pDM803 and pBY520 by microprojectile bombardment. Fourty-two transgenic lines had been obtained. The highest efficiency of transformation reached to 3.7% for cv. Md, 2.8% for cv. Gm, and 5 % for cv. Bd. The micro nutriment of Cupric had significant effect on transformation. The embryogenic callus cultured in dim-light condition had higher transformation efficiency than the green callus cultured in light condition for one month before transformation. The selective regime and selective pressure on the putative transgenic plants were important for obtaining the desire number of transgenic plants. It also affected the copy number of integrated genes in the genomic DNA of transgenic plants.

冷地型草坪草耐热机理初探——Ⅰ.草地早熟禾(Poa pratensis L.)在热境胁迫下叶片叶绿素含量和POD酶活性的变化

草地早熟禾在持续高温（37～38℃）胁迫下表现为叶绿素相对含量下降,POD酶活性在处理2d时表现为下降,4d及4d后则明显提高。耐热品种较不耐热品种的叶片POD酶活性无论是适温（25℃）还是高温（38℃）下一般均较高。热境下有较高的POD酶活性可能是植株体耐热的主要原因之一。

Callus induction and plant regeneration from mature bluegrass (Poa pratensis L.) seeds

A protocol was discussed for high efficient plant regeneration from seven bluegrass （Poa pratensis L.） cultivars via an in- direct callus induction and somatic embryogenesis method. Mature seeds were used as explants for callus initiation. Callus induction and proliferation efficiencies were investigated on NB, modified MS （MMS） and MS media, supplemented with 2.0 mg·L^-1 2,4-dichlorophenoxyacetic acid （2,4-D）. The MMS medium performed best. Based on the MMS medium, direct and indirect callus induction effects of bluegrass from mature seeds were compared at the range of 1-5 mg·L^-1 2,4-D contained in the medium. Under the direct callus induction method, the most suitable 2,4-D concentrations varied among cultivars. Under the indirect callus induction method, a significantly high callus induction frequency （93.33%-98.33%） was obtained and there were barely any statistically sig- nificant differences among the tested genetically diverse cultivars. Somatic embryos were promoted on the MMS medium supple- mented with 3 mg·L^-1 2,4-D, 0.1 mg·L^-1 kinetin and 0.8 mg·L^-1 CuSO4. Embryogenetic calli developed into plantlets on the MMS medium containing different concentrations of thidiazuron （TDZ）, and the differentiation frequencies varied in the range from 20.15% to 77.65%. The 0.25 mg·L^-1 TDZ was generally the most suitable concentration for the tested cultivars.

Genetic Relationships in Advanced Generation Hybrids Derived from Crosses between Texas (<i>Poa arachnifera</i>) and Kentucky (<i>Poa pratensis</i>) Bluegrass Using ISSR Markers

Fertile, advanced generation hybrids derived from crosses between Texas (Poa arachnifera Torr.) and Kentucky (Poa pratensis L.) bluegrass have been selected. The hybrids are currently being evaluated for low-input turf potential. Since they are derived from hand-harvested seed from first-generation hybrids located in field nurseries their exact genetic origin is unknown. This experiment was conducted to determine if there are still genetic relationships among the advanced generation hybrids and some of the Texas and Kentucky parents in their pedigrees. Four Inter Simple Sequence Repeat (ISSR) primer combinations resolved on 6% nondenaturing polyacrylamide gels resulted in 179 polymorphic bands that were scored to create a genetic similarity matrix and dendrogram based on Jaccard’s coefficient. The clustering of the advanced generation hybrids was generally in agreement with what would be expected based on their pedigrees and indicated it was more likely to select a fertile hybrid from an advanced generation, rather than the F1 generation.

Distribution Area and Yield Indicators of Poa bulbosa L. in Uzbekistan

The article is based on field research, existing literature, and samples of herbarium kept in the National Herbarium fund (TASH) Poa bulbosa L. The distribution maps and productivity indicators in the flora of Uzbekistan are presented. As you know, Poa bulbosa L. is considered the wild relative of cultural plants, as a forage plant, it is a plant with high protein value. In the course of research during 2021-2022, in 16 areas, the yield indicators of the species were determined. In the studied research areas, indicators of the total weight of plant bushes (on the account of wet mass) and, respectively, the volume of plant biomass (on the account of dry mass, the upper part of 25%) were determined. According to him, it was determined that the average yield of the plant the wet mass is 14669.8 kg/ha, and the average yield of the plant the dry mass in areas of total 244.0 ha in the total area is 63172.5 kg.

Analysis of drought resistance HVA1 gene under drought stress in different Poa pratensis cultivars

Total RNA from leaves of Poapratensis cultivars under drought stress was extracted for reversing transcription to cDNA and then cDNA as template for PCR reaction by designing primer of cds of Hordeum valgare HVA1 drought resistance gene from GenBank. The amplified products were positive recon identified by using procedures of recovery, connection, transformation and enzyme separation. The length of cloned gene sequence was 324 bp, identity reached 79.27% with Barley HVA1 gene that meaned the cloned gene sequence was the partial HVA1 gene of Poapratensis.

The Complete Chloroplast Genome of <i>Poa pratensis</i>(Poaceae), a High-Quality Forage

Poa pratensis L. (Poaceae) is a hardy, persistent, attractive forage and turf grass adapted to a wide range of soils and climate. In this study, we release and detail the complete chloroplast genome sequences of P. pratensis. The whole chloroplast genome was 135,649 bp in length and comprised 131 genes, including 85 protein-coding genes, 38 tRNA genes, 8 rRNA genes. The P. pratensis chloroplast genome had a GC content of 38.3%. The result of phylogenetic analysis showed that P. pratensis was closely related to P. pratensis cv. Qinghai and P. poophagorum. This study would provide useful genetic information for the protection of P. pratensis and other related species.

Target-site Mechanisms Involved in Annual Bluegrass(Poa annua L.) Tolerance to Fenoxaprop-P-ethyl

Annual bluegrass （Poa annua L.） was found to be tolerant to fenoxaprop- P-ethyl as well as quizalofop-P-ethyl, haloxyfop-R-methyl, clodinafop-propargyl, fluaz- ifop-P-butyl, cyhalofop-butyl, sethoxydim and tralkoxydim, whereas it was sensitive to clethodim and tepraloxydim. The acetyI-CoA carboxylase （ACCase） IC50 values of five P. annua biotypes were 10.46 to 11.98-fold higher than the susceptible Japanese foxtail （Alopecurus japonicus Steud.）. The presence of the polymorphic lie and Leu at 1 781, which the presence of Leu at 1 781 had been reported to be in- volved in the resistance of grass weeds to ACCase inhibitors, was subsequently i- dentified in the ACCase of P. annua. Furthermore, the expression level of gene that encoding P. annua ACCase was found to be approximately 4.67 to 7.37-fold higher than A. japonicus, possibly explaining the P. annua target site tolerance to fenoxaprop-P-ethyl.

Effects of traffic pollution on the genetic structure of Poa annua L.populations

The genetic composition of Poa annua L. populations with a series of traffic pollution was studied by starch electrophoresis. Five enzyme systems were stained. The results showed that: (1) Traffic pollution can dramatically change genotypic frequencies at some loci of P. annua populations. Significant deviations from Hardy Weinberg equilibrium were observed on loci Fe 1 and Me due to the excess of heterozygotes in some populations. (2) The effective number of alleles per locus and the observed and expected heterozygosity were higher in the pollution series than in the clear control site(Botanic Park population), but the increase was not related with the pollution extent. (3) Most genetic variation was found within populations, and only 6 21% was among populations of the polluted series. Slightly higher differentiation( F ST =7 98%) was observed when the control population was included. (4) The calculated gene flow(Nm) is 2 8841 per generation. The mean of genetic identity is 0 9864 and the genetic distance average to 0 0138

Effects of Different Herbicides on the Control of Malachium aquaticum L. and Poa annua L.

In this experiment,the effects of 13 kinds of herbicides( or mixtures) on the control of two kinds of weeds were studied by pot cultivation with the broadleaf weed Malachium aquaticum L. and Gramineae weed Poa annua L. as the materials. The results showed that the herbicide MCPA-Na had the best and fastest control effect on M. aquaticum L.,and all the M. aquaticum L. died 7 d after treatment;it was followed by the other four herbicides including MCPA-Na + clethodim,MCPA-Na + quizalofop-p-ethyl,bentazon and nicosulfuron·atrazine,and all the M. aquaticum L. died 14 d after treatment. Atrazine was the best herbicide to control Gramineae weeds,followed by nicosulfuron·atrazine,and mesotrione·nicosulfuron·atrazine. The study on the application of field herbicide found that four herbicides including atrazine,mesotrione·nicosulfuron·atrazine,nicosulfuron·atrazine and bentazon had better control effect on weeds. The best herbicide for flax field was MCPA-Na + clethodim,followed by MCPA-Na and MCPA-Na + quizalofop-p-ethyl. The optimized herbicides and combinations had no harmful effects on the growth of corn and flax.

硝酸钾配施有机肥对早熟禾生长及养分吸收的影响

早熟禾草坪在盐碱土壤上建植3~4年后会发生明显的退化,研究园林养护中采用硝酸钾配施有机肥的方式为其提供营养,对促进植株生长和提高坪用质量具有重要意义。试验设置在城市绿化带中,设置空白对照(K1)、硝酸钾化肥对照(K2)、化肥+发酵饼肥(K3)、化肥+腐殖酸复混肥(K4)4个处理,每个处理3次重复,研究了早熟禾生长和养分吸收变化。结果表明:K3与K1相比,在7~10月有利于提高早熟禾干物质积累量、含水量、叶绿素a、叶绿素b和类胡萝卜素含量,显著提高了植株氮、磷、钾吸收量;K3与K2相比,在8~9月显著提高了干物质积累量,7月和10月显著提高了叶绿素b和类胡萝卜素含量,8~10月提高了氮磷钾养分吸收量;K3与K4相比,在7~9月提高了干物质积累量,7~10月显著提高了叶绿素b和类胡萝卜素含量,促进了氮磷钾营养元素的吸收。综合分析认为,硝酸钾配施发酵饼肥为适宜施肥处理。

硝酸钾配施发酵饼肥对景观草坪坪用质量的影响

通过研究硝酸钾配施发酵饼肥对草地早熟禾草坪坪用质量影响的规律,可以为城市园林草坪养护的科学施肥提供理论依据。试验在城市环境条件下,设置对照(CK)、硝酸钾(K_(1))、硝酸钾+发酵饼肥(K_(2))、硝酸钾+腐殖酸复混肥(K_(3))4个处理,小区试验设计,3次重复。结果表明:6月,K_(1)处理分蘖密度、株高、叶长、叶绿素含量均显著高于CK、K_(2)和K_(3)处理;7-10月,K_(2)分蘖密度显著高于CK、K_(1)和K_(3),6-8月K_(1)与K_(3)均显著高于CK;6-10月,K_(2)处理盖度显著高于CK,6-7月和9-10月K_(2)显著高于K_(1);7-10月K_(2)株高和叶长均显著高于CK,8月和10月K_(2)显著高于K_(1);7月、8月和10月,K_(2)处理叶宽显著高于对照;7-10月,K_(2)处理叶绿素含量和植株鲜重均显著高于CK,K_(2)显著高于K_(3)。综合分析认为,在现有施肥量基础上硝酸钾与发酵饼肥配合施用有利于显著提高草地早熟禾草坪坪用质量。

草地早熟禾苗期耐低温的生理特性研究

为了探究不同抗性草地早熟禾苗期对低温胁迫的生理特性差异,以10个常用草地早熟禾品种为试验材料,将幼苗叶片进行不同程度的低温胁迫处理,利用细胞伤害率和对应的低温度梯度进行Logistic方程拟合,获得半致死温度(LT50)并筛选抗寒品种和低温敏感品种,并以二者为试验材料进行相关生理指标的测定和相关性分析。结果表明,草地早熟禾‘普瑞芬’的LT_(50)为-17.5℃,表现出较好的抗寒性,‘帝国’的LT_(50)为-3.2℃,表现出对低温的敏感性;经低温胁迫处理后抗寒品种‘普瑞芬’的相对电导率和丙二醛含量显著下降并低于低温敏感品种‘帝国’,而‘普瑞芬’幼苗中干物质含量、相对含水量和苗长等生长指标和叶绿素含量、渗透调节物质(游离脯氨酸、可溶性糖和可溶性蛋白)和抗氧化酶活性(SOD、POD和CAT)均高于‘帝国’;经相关性分析表明,低温对草地早熟禾幼苗的干物质,苗长和根长及渗透调节物质含量影响较大且各指标之间相互作用。

草地早熟禾PpSWEET1b基因克隆及功能研究

SWEETs糖转运蛋白是一类在真核生物和原核生物中均存在的促进糖通过细胞膜流动的转运蛋白之一,参与调控植物的生长发育和胁迫响应过程。以草地早熟禾品种蓝月为材料,以叶片cDNA为模板克隆PpSWEET1b基因,采用花序侵染法转化拟南芥,获得了PpSWEET1b拟南芥过表达株系,并研究干旱和低温胁迫对转基因和野生型拟南芥生长、生理及基因表达的影响。结果表明:干旱和低温胁迫下,PpSWEET1b过表达植株生长状态均优于野生型,叶片MDA含量显著低于野生型,但葡萄糖含量较野生型显著增加,抗旱性和抗寒性明显增强;PpSWEET1b过表达植株可能协同SWEET2和SWEET3共同参与了对低温的响应。此外,以叶片DNA为模板克隆了PpSWEET1b基因的启动子序列,顺式作用元件预测发现,其含有多个与胁迫和激素响应、光响应相关的元件。综合以上结果表明,草地早熟禾PpSWEET1b基因在耐旱和耐寒方面发挥着重要作用,可为草坪草抵抗非生物胁迫生物育种提供新的优异基因资源。

磷添加对青海扁茎早熟禾各器官生物量及生态化学计量特征的影响

磷对植物体内氮代谢和氮效率均有促进作用,添加适量的磷肥有助于提高牧草产量和抗逆性。为探究不同磷添加下牧草不同器官生物量及元素浓度的变化规律,本研究设置7个磷添加梯度(0、30、60、90、120、150、180 kg/hm^(2)),分析了5龄青海扁茎早熟禾各器官(根、茎、叶)生物量的分配、生态化学计量特征及二者的相互关系。结果表明:(1)施磷量的增加能够显著影响青海扁茎早熟禾生物量,呈先增加后降低变化趋势:其中90 kg/hm^(2)施磷水平下地上和地下生物量最高,分别比对照增加73.99%、7.31%;(2)随施磷量增加,青海扁茎早熟禾各器官碳、氮、磷含量呈先增加后降低的变化趋势:其中150 kg/hm^(2)施磷水平下,根系氮和磷含量最高,较对照组增加37.05%和34.63%,而90 kg/hm^(2)水平下,叶片氮和磷含量最高,分别比对照增加11.60%和37.66%;(3)不同器官碳、氮、磷含量存在较大差异:其中,叶片碳、氮含量高于根系,而根系磷含量却高于叶片;(4)各器官生物量与碳、氮、磷含量呈显著正相关性(P<0.05),地上植株生物量(叶片、茎秆)与碳氮比、碳磷比呈极显著负相关性(P<0.01)。由此可见,磷添加能显著调控青海扁茎早熟禾营养元素吸收和平衡能力,适度磷添加(90 kg/hm^(2))对高效利用高龄青海扁茎早熟禾具有重要的生态和生产意义。

外源谷胱甘肽对白粉菌胁迫下草地早熟禾抗氧化系统的影响

草地早熟禾(Poa pratensis L.)白粉病的发生严重影响其观赏价值和使用年限。谷胱甘肽(Glutathione,GSH)作为植物体内关键的抗氧化剂在植物抵御病原菌侵染过程中起重要作用。为探讨外源GSH调控下植物抗氧化系统在草地早熟禾抗白粉病中的角色,本研究以草地早熟禾中抗品种‘太行’和极感品种‘探险家’为材料,通过喷施0.1 mmol·L^(-1)和1.6 mmol·L^(-1)外源GSH,测定接种白粉菌后3 d和7 d植物抗氧化系统相关指标。结果表明在白粉菌侵染早期施用0.1 mmol·L^(-1) GSH后草地早熟禾的超氧化物歧化酶(Superoxide dismutase,SOD)活性与抗病性呈负相关关系,过氧化物酶(Peroxidase,POD)活性与抗病性呈正相关关系;谷胱甘肽过氧化物酶(Glutathione peroxidase,GPX)和谷胱甘肽巯基转移酶(Glutathione S-transferase,GST)活性显著提高(P<0.05),0.1 mmol·L^(-1) GSH处理下草地早熟禾抗病能力更强。本研究明确了外源GSH通过调控草地早熟禾抗氧化系统增强白粉病抗性的生理生化机制,为防治草地早熟禾白粉病提供了理论依据。

草地早熟禾无融合生殖胚囊发育的转录组学分析

为探究草地早熟禾无融合生殖胚囊发育过程中基因表达谱的变化,本研究利用高通量Illu-mina Hiseq测序技术对‘清水’草地早熟禾无融合生殖子房发育的无孢子起始细胞发生时期(8DBA)和无孢子生殖胚囊发育时期(6DBA、4DBA和2DBA)共4个阶段的小穗进行转录组测序。结果显示,不同差异分组(2DBA vs 4DBA、2DBA vs6DBA和2DBA vs 8DBA)共有13575个DEGs,包括7191个上调基因和6384个下调基因。GO富集分析发现,3个差异分组的DEGs显著富集在过氧化氢的响应、蛋白质重折叠、营养水库活动、错误折叠蛋白结合和双糖生物合成等过程中。KEGG通路分析表明,3个差异分组的DEGs显著富集在代谢途径、次生代谢产物的生物合成、淀粉和蔗糖代谢及内质网中的蛋白加工等通路上,在2DBA vs 8DBA分组中发现植物激素信号转导途径的富集。4个时期占比最多的转录因子家族是NAC、AP2/ERF-ERF和MYB-related等。将在4个发育阶段特异性高表达的基因OPR1、ASN2、SAMS2、HSP81-2、PXG4和FPK2作为与‘清水’草地早熟禾无融合生殖胚囊发育相关的候选基因。qRTPCR分析表明,除WOX2在4DBA上调,与RNA-seq的表达存在差异外,其余16个DEGs的表达量变化趋势与高通量测序结果基本一致。

Agrobacterium-mediated Transformation of Kentucky Bluegrass

Embryogenic calli of Kentucky bluegrass, named Md, were induced from mature seeds and embryos, and proliferated on medium K3 containing 2,4-dichlorophenoxyacetic acid (2,4-D, 10.0 mumol/L), 6-benzylaminopurine (BAR, 0.5 mumol/L) and K5 which was the K3 medium supplemented with cupric sulfa (0.5 mumol/L) under dim-light condition (20-30 mumol.m(-2).s-1, 16 h light) at 24 degreesC. Embryogenic calli were transformed with plasmids pDM805 Carring bar and gus genes, Which was mediated by an Agrobacterium strain AGL1, four transgenic lines were obtained. The important factors that affect the transformation efficiency and obtain desirable number of transgenic plants included: (1) the quality of embryogenic calli; (2) light condition and time of co-cultivation; (3) concentration of antibiotics used for suppressing the overgrowth of Agrobacterium in the course of transformed plant regeneration; (4) selection pressure, etc. The micro nutrient of cupric had significant influence on the quality of embryogenic calli. This presentation is the first successful protocol of Kentucky bluegrass transformation mediated by Agrobacterium.

接种丛枝菌根真菌对不同生育期牧草生长的影响

为探究接种丛枝菌根真菌(Arbuscular mycorrhizal fungi,AMF)对不同生育期牧草生长的影响,本研究选取无芒雀麦(Bromus inermis)、冰草(Agropyron cristatum)、羊草(Leymus chinensis)和草地早熟禾(Poa pratensis)4种牧草进行盆栽试验,分别在苗期、拔节期和刈割后拔节期进行取样,测定植物生物量、菌根侵染率和菌丝密度等指标。结果表明:与不接种AMF相比,接种AMF显著提高了无芒雀麦和羊草的地上与地下生物量,但对刈割后拔节期冰草和草地早熟禾的地上和地下生物量无显著影响;4种牧草在不同生育期下菌根响应均为正效应,但是刈割后拔节期冰草、羊草和早熟禾菌根生长响应显著降低;4种牧草根系的菌根侵染率随生育期均呈增加趋势;刈割后拔节期土壤菌丝密度达到最高。因此,AMF与植物的共生关系具有物种特异性,共生作用随着生育期发生改变,随着生育期根内和根外AMF丰度增加,但菌根生长响应下降,说明AMF对植物幼苗有更强的促生作用,而这种促生作用与AMF丰度无关。