烟草叶斑病菌Cumuliphoma indica的生物学特性及室内药剂筛选

烟草是重要的经济作物,其叶具有较高的经济价值。近年来,随着烟草种植面积增加,叶部病害种类呈上升趋势。前期从广西壮族自治区贺州市烟区烟叶病样中分离得到2株烟草叶斑病致病菌,经多基因系统发育分析,确定为Cumuliphoma indica,是国内关于该病原菌引起烟草叶斑病的首次报道。为明确该病原菌的生物学特性并筛选防治药剂,本研究采用菌丝生长速率法,研究分离菌株菌丝的致死温度,以及其在不同培养基、温度、pH、碳源、氮源、光照周期条件下的生长情况,并测定病原菌对9种化学药剂的敏感性。生物学特性研究结果表明:C.indica菌丝生长的温度范围广,最适温度为28℃;弱酸性环境更利于菌丝生长,最适pH为5;在玉米粉琼脂培养基(CMA)和察氏培养基(CDA)上生长最快;最适氮源为蛋白胨;最适碳源为可溶性淀粉;菌丝致死温度为49℃,水浴10 min;光照对菌丝生长有显著影响,24 h全光照对其最有利。室内防治药剂筛选结果表明:9种供试杀菌剂对C.indica菌丝生长均有不同程度的抑制作用,其中50%啶酰菌胺WG抑菌效果最好,EC_(50)为0.025 mg/L;其次分别是50%咯菌腈FS(0.084 mg/L)、500 g/L异菌脲SC(0.217 mg/L)、450 g/L咪鲜胺EW(1.354 mg/L)、80%代森锰锌WP(6.565 mg/L)、10%苯醚甲环唑ME(9.576 mg/L)、25%吡唑醚菌酯(34.237 mg/L)和40%腈菌唑SC(38.804 mg/L);430 g/L戊唑醇SC的抑制作用最弱,EC50为42.574 mg/L。本研究揭示了C.indica的生物学特性,推荐50%啶酰菌胺WG作为防治候选杀菌剂,本结果可为由C.indica引起烟草叶斑病的有效防治提供参考和依据。

Synthesis of plant-based biogenic jarosite nanoparticles using Azadirachta indica and Eucalyptus gunni leaf extracts and its application in Fenton degradation of dicamba

Bio-jarosite,an iron mineral synthesized biologically using bacteria,is a substitute for iron catalysts in the Fenton oxidation of organic pollutants.Iron nanocatalysts have been widely used as Fenton catalysts because they have a larger surface area than ordinary catalysts,are highly recyclable,and can be treated efficiently.This study aimed to explore the catalytic properties of bio-jarosite iron nanoparticles syn-thesized with green methods using two distinct plant species:Azadirachta indica and Eucalyptus gunni.The focus was on the degradation of dicamba via Fenton oxidation.The synthesized nanoparticles exhibited different particle size,shape,surface area,and chemical composition characteristics.Both particles were effective in removing dicamba,with removal efficiencies of 96.8%for A.indica bio-jarosite iron nano-particles(ABFeNPs)and 93.0%for E.gunni bio-jarosite iron nanoparticles(EBFeNPs)within 120 min of treatment.Increasing the catalyst dosage by 0.1 g/L resulted in 7.6%and 43.0%increases in the dicamba removal efficiency for EBFeNPs and ABFeNPs with rate constants of 0.025 min^(-1) and 0.023 min^(-1),respectively,confrming their catalytic roles.Additionally,the high efficiency of both catalysts was demonstrated through five consecutive cycles of linear pseudo-first-order Fenton oxidation reactions.

Study of Some Biodemographic Parameters of Caryedon serratus Olivier (Coleoptera: Chrysomelidae) Insect Pest of Tamarind (Tamarindus indica Lin.) Fruit, in Burkina Faso

The lack of food security leads us to turn to the riches of the forest, namely non-timber forest products (NTFP) and timber forest products (TFP). In Burkina, these products are a source of income for families, improving their living conditions. Tamarindus indica L. that is a NFTP, is widely used in both rural and urban areas. Unfortunately, tamarind is subject to attack by Caryedon serratus. Its biological activity begins on the fruit before the harvest. The aim of our study is to evaluate some biodemographic parameters of the insect pest C. serratus Olivier. First100 healthy T. indica pods were placed in contact with ten pairs of C. serratus for 24 hours. 25 pods, each carrying a maximum of two eggs, were divided into five batches of 5 pods. Then a pair of C. serratus aged less than 24 h was placed in contact with 4 healthy pods for 24 h. Every day, the pair was removed and transferred to another box containing 4 new healthy pods. A total of 20 replicates were performed. The results showed that C. serratus has an average lifespan of 14 days. However, the female (16 days) lived longer and laid an average of 34 eggs during her lifetime. The egg-laying period lasted 14 days, the number of eggs increased until reaching a maximum peak on the 4th day. C. serratus has an embryonic development time of 3 days and an emergence rate of 66.63%. However, the weight of males and females differed significantly (p = 0.0108). We found an intrinsic rate of natural increase of 0.12 and a population doubling time was 5.68 days. These results have enabled us to gain a better understanding of its development cycle and its capacity for regeneration. This allows us to implement control strategies for better stock protection.

基于优化MaxEnt模型的板齿鼠Bandicota indica在中国适生区预测与分析

板齿鼠Bandicota indica对农作物危害极大,传播多种人兽共患疾病且扩散能力强。及时掌握板齿鼠种群动态及其分布区动态,对其监测、预警及防控具有参考意义。本文对板齿鼠分布数据的筛选方法和MaxEnt模型参数的设置进行优化,使用R软件的ENMeval程序包对48个参数组合进行测试,筛选出构建MaxEnt模型的最优参数。基于板齿鼠分布数据和参数优化的MaxEnt模型预测板齿鼠在中国适生区的分布,结果表明,板齿鼠在中国的适生区分布于广东、广西、台湾地区、福建、云南、四川、贵州、江西、海南、西藏、浙江等地,总面积为68.6万km^(2),占研究区面积的7.23%左右。最暖季降水量、等温性和年均温是影响板齿鼠分布的主导环境因子。本研究不仅模拟了板齿鼠在我国的潜在地理分布,更为该鼠的分布与环境变量之间关系的研究提供了理论参考。

Grain yield,nitrogen use efficiency and physiological performance of indica/japonica hybrid rice in response to various nitrogen rates

Utilizing the heterosis of indica/japonica hybrid rice(IJHR)is an effective way to further increase rice grain yield.Rational application of nitrogen(N)fertilizer plays a very important role in using the heterosis of IJHR to achieve its great yield potential.However,the responses of the grain yield and N utilization of IJHR to N application rates and the underlying physiological mechanism remain elusive.The purpose of this study was to clarify these issues.Three rice cultivars currently used in rice production,an IJHR cultivar Yongyou 2640(YY2640),a japonica cultivar Lianjing 7(LJ-7)and an indica cultivar Yangdao 6(YD-6),were grown in the field with six N rates(0,100,200,300,400,and 500 kg ha^(-1))in 2018 and 2019.The results showed that with the increase in N application rates,the grain yield of each test cultivar increased at first and then decreased,and the highest grain yield was at the N rate of 400 kg ha^(-1)for YY2640,with a grain yield of 13.4 t ha^(-1),and at 300 kg ha^(-1)for LJ-7 and YD-6,with grain yields of 9.4–10.6 t ha^(-1).The grain yield and N use efficiency(NUE)of YY2640 were higher than those of LJ-7 or YD-6 at the same N rate,especially at the higher N rates.When compared with LJ-7 or YD-6,YY2640 exhibited better physiological traits,including greater root oxidation activity and leaf photosynthetic rate,higher cytokinin content in the roots and leaves,and more remobilization of assimilates from the stem to the grain during grain filling.The results suggest that IJHR could attain both higher grain yield and higher NUE than inbred rice at either low or high N application rates.Improved shoot and root traits of the IJHR contribute to its higher grain yield and NUE,and a higher content of cytokinins in the IJHR plants plays a vital role in their responses to N application rates and also benefits other physiological processes.

Dry matter production and panicle characteristics of high yield and good taste indica hybrid rice varieties

Indica hybrid rice(Oryza sativa) production aims to achieve two crucial targets: high yield and good taste. This study selected three types of indica hybrid rice according to grain yield and taste value, including high yield and good taste(HYGT), low yield and good taste(LYGT), and high yield and poor taste(HYPT), to analyze yield components,corresponding growth characteristics, and rice taste quality. When values were averaged across varieties and years,there were almost no differences in taste value between HYGT and LYGT;HYGT showed a significant increase in yield,owing to a higher number of panicles and spikelets per panicle, with a respective increment of 16.2 and 20.6%. The higher grain yield of HYGT compared with LYGT was attributed to three key factors: a higher leaf area index(LAI) during heading, a higher ratio of grain to leaf, and a higher biomass accumulation at maturity. HYGT and HYPT achieved similar high yields;however, HYGT had more panicle numbers and lower grain weight. In addition, HYGT showed a significantly higher taste value than HYPT, attributed to its significantly lower protein and amylose contents, with reductions of 8.8and 15.7%, respectively. Lower protein and amylose contents might be caused by a proper matter translocation from vegetative organs to panicle. This study suggested that reasonable panicle characteristics and translocation efficiency from vegetative organs to panicle during heading to maturity are the key factors in balancing yield and rice taste quality.These results will provide valuable insights for rice breeders to improve the grain yield and quality of indica hybrid rice.

Molluscicidal effect of green synthesized silver nanoparticles using Azadirachta indica on Biomphalaria alexandrina snails and Schistosoma mansoni cercariae

Objective:To assess the molluscicidal effect of the eco-friendly green synthesized neem silver nanoparticles(neem-Ag NPs)against Biomphalaria alexandrina,the snail intermediate host for Schistosoma mansoni,and their cercaricidal potential.Methods:Methanol extracts from neem fruits were used for green synthesis of neem-Ag NPs.The neem-Ag NPs were characterized using UV-visible absorption spectra,dynamic laser light scattering technique,and transmission electron microscopy.The potential molluscicidal effect against adult and juvenile Biomphalaria alexandrina and the effect of the sub-lethal concentration on hatching of snail eggs and Schistosoma mansoni cercariae were evaluated.Results:The surface plasmon resonance of neem-Ag NPs showed a sharp absorption peak atλ_(max)=518 nm together with multiple peaks.The hydrodynamic diameter was(77.15±34.53)nm,the polydispersity index(0.338±0.000)and the zeta-potential-14.07 mV.Moreover,transmission electron microscopy showed that the average size of the nanoparticles was(27±2)nm.Agglomeration was evident and a light-colored capping layer could be seen coating the nanoparticles.Juvenile snails(LC_(50):0.83 ppm)were more susceptible to neem-Ag NPs than adults(LC_(50):1.07 ppm).In addition,neem-Ag NPs and neem at LC_(50)concentrations inhibited the egg-hatching of snails and showed cercaricidal activity in a time-dependent manner.Conclusions:Neem-Ag NPs have lethal activities against Biomphalaria alexandrina snails and their eggs,as well as Schistosoma mansoni cercariae.Hence,neem-Ag NPs could be a potential agent to control schistosomiasis.

Biocontrol potential of entomopathogenic nematode,Heterorhabditis indica against pink bollworm,Pectinophora gossypiella(Saunders)(Lepidoptera:Gelechiidae)

Background The emergence of pink bollworm(PBW),Pectinophora gossypiella(Saunders)(Lepidoptera:Gelechiidae),in cotton due to Bt resistance and concealed feeding habit has created a need for alternative,eco-friendly,and cost-effective control methods.This study aimed to evaluate the bio-efficacy and reproductive potential of two native strains of entomopathogenic nematodes(EPNs),Heterorhabditis indica,namely CICR-HI-CL and CICR-HI-MN,against PBW larvae and pupae under in-vitro conditions.Results The larval assay revealed that strain CICR-HI-CL exhibited higher potency than strain CICR-HI-MN against 2nd,3rd,and 4thinstar larvae,with median lethal dose(LD50)values of 5.45,4.45,and 4.60 infective juveniles(IJs)per larva,respectively.In case of pupal bioassay,both EPN strains demonstrated greater virulence when applied directly(LD50values:29.65 and 73.88 IJs per pupa for strains CICR-HI-CL and CICR-HI-MN,respectively)compared to soil application(147.84 and 272.38 IJs per pupa).Both EPN strains successfully penetrated and reproduced on 4thinstar larvae,resulting in maximum production of 19.28 and 20.85 lakh IJs per larva in the next generation when inoculated at 30 IJs per larva.Conclusion The present study has generated useful information on the virulence and reproductive potential of two strains of EPN H.indica(CICR-HI-CL and CICR-HI-MN)against PBW,a dreaded pest of cotton.Higher virulence and reproductive potential of EPN strains demonstrated their ability to multiply,sustain and perpetuate on larval and pupal stages of PBW.The knowledge generated will help formulate effective management strategies for PBW with the inclusion of EPN as a potential biological control candidate.The soil-dwelling life stages viz.,last instar hibernating larvae and pupae of PBW can be the ideal weak links to make a successful use of H.indica for sustainable management of PBW in the cotton ecosystem.However,before taking these EPN strains to field for managing PBW,detailed studies investigating their biocontrol potential against PBW under field conditions are needed.

广西芒果细菌性坏死病病原菌鉴定

芒果Mangifera indica L.是我国著名的热带水果,近年来细菌性病害发生严重。2020年-2021年对广西百色地区的芒果病害进行调查发现,一种细菌性坏死病与细菌性黑斑病混合发生,一般发病率30%~60%,严重可达90%以上。本研究先后从该地区不同芒果坏死病组织中分离得到泛菌属的21株细菌。根据形态、生理生化特性、16S rDNA、fusA、gyrB、leuS、pyrG、rlpB和rpoB的多基因系统发育分析、致病性测定等方法将21个菌株分别鉴定为Pantoea vagans、P.anthophila、P.dispersa和P.cypripedii。其中P.anthophila、P.dispersa和P.cypripedii引起芒果细菌性坏死病是中国首次报道。

施氮量对优质稻G优325氮肥利用率和产量的影响

【目的】探明优质杂交籼稻新品种G优325的适宜施氮量。【方法】设5个施氮量处理(0、60、120、180和240 kg/hm^(2),分别记为N0、N60、N120、N180和N240)进行田间试验,研究不同施氮量对G优325主要生育时期茎糵数、干物质积累与转运能力、氮肥吸收利用率和产量及其构成因素的影响。【结果】适当增加施氮量能显著提高G优325的产量,且在N180处理下产量最高。施氮量对产量构成因素、茎蘖数和干物质积累总量影响显著,随着施氮量增加,G优325成熟期的有效穗数、每穗总粒数和干物质积累总量均表现为先增加后降低的趋势,且有效穗数和干物质积累总量均在N180处理达到最高值,而每穗粒数在N120处理最多。随着施氮量增加,抽穗前后的干物质积累向籽粒的转运量均表现为处理N180>N240>N120>N60>N0;拔节期、抽穗期和成熟期的氮素积累总量均表现为先增加后降低的趋势,且均在N180处理下最高;氮素干物质生产效率、氮素稻谷生产效率、氮素收获指数、氮肥吸收利用率、氮肥农学利用率、氮肥偏生产力和氮素生理利用率均表现为处理N0>N60>N120>N180>N240。【结论】适宜提高施氮量(180 kg/hm^(2)),可协同实现优质杂交籼稻新品种G优325高产与较高氮肥利用效率。

Performance of Five Early Indica Rice Varieties under Direct Seeding in Jiangbei District

Comparative experiments were conducted on five conventional indica rice varieties,including Yongxian 15,Zhongzao 39,Shunda 135,Zhongzu 143,and Zhongzu 18.Under direct seeding conditions,their growth period and yield performance were investigated.The results showed that the yield of Zhonggang 143 and Shunda 135 was higher than that of Yongxian 15(CK),and Zhonggang 143 had the highest yield of 7.494 t/hm 2,followed by Shunda 135(7.467 t/hm 2);Yongxian 18(CK)has a yield of 7.326 t/hm 2.Taking into account factors such as field growth,yield,and growth period,Zhongzu 143 and Shunda 135 can be further promoted to optimize the early rice variety structure in Jiangbei District.

Diversity of Flower Opening Time and Duration in Rice (Oryza sativa ssp. indica) Landraces of South and Southeast Asia in Different Cultivation Seasons

Different cultivars of rice(Oryza sativa)open at different times of the day,and the overlap of anthesis time in rice between the neighbouring cultivars is of crucial importance to the degree of cross pollination in rice.Nevertheless,none of the past experiments with cross pollination between different rice cultivars ever reported the respective flower opening time(FOT)and flower exposure duration(FED)of the parent cultivars,until recently.The authors present here the first record of FOT and FED of 1114 indica rice landraces of South and Southeast Asia,growing during sum-mer and winter seasons in three consecutive years.The authors also present an analysis of the influences of the grow-ing season on the anthesis behaviour,and present the first records of the FOT and FED variability on sunny and cloudy days of a large number of landraces.The data show that rice florets tend to open later in the morning(that is,take longer time to anthesis after sunrise)on sunny days than on cloudy days,and also significantly later during long day seasons(spring and summer)than during short day season(winter);and that FED is inversely related to both FOT and the length of duration from sunrise to first flower opening.The wide ranges of FOT(8:50 a.m.to 12:40 p.m.)and FED(15 to 194 minutes)also suggest the ample time window for receiving pollen from neighbouring cultivars with differ-ent FOT,enhancing the chances of cross pollination between hundreds of rice landraces with FOT and FED overlaps.

弱光下烯效唑对杂交籼稻茎秆形态、解剖特征和抗倒伏性的影响

【目的】研究弱光胁迫下外源喷施烯效唑对杂交籼稻植株内源激素、茎秆解剖和形态特征及抗倒伏性的调控效应,为四川盆地弱光环境下杂交籼稻丰产稳产及应急化控栽培提供理论依据和技术支撑。【方法】于2018—2019年,以四川盆地主推品种渝香203(三系杂交籼稻)和C两优华占(两系杂交籼稻)为材料,设置光照、烯效唑和品种的三因子互作大田裂裂区试验,遮阴为主区,设置正常光照(NL)和遮阴处理(S,遮光率为50%);以叶面喷施烯效唑为副区,设置烯效唑溶液梯度分别为0(U0)、40 mg·L^(-1)(U40)和80 mg·L^(-1)(U80),以品种为副副区,分别为渝香203和C两优华占,比较不同处理茎秆倒伏指数,并从茎秆形态、解剖结构和内源激素等方面剖析植株抗倒伏性差异的原因。【结果】遮阴和烯效唑对两杂交籼稻品种茎秆形态解剖结构、内源激素和抗倒伏性均具有显著的调控作用。较正常光照,遮阴处理显著提高杂交籼稻茎秆倒伏指数,归因于折断弯矩显著降低,尽管弯曲力矩亦显著降低,品种渝香203差异较明显。基节横切面茎秆机械组织、大小维管束面积显著降低,纵切面茎秆细胞宽度减小,导致细胞长宽比增加,茎壁厚度减小,从而显著降低了遮阴胁迫下茎秆机械强度。遮阴下,烯效唑处理显著降低杂交籼稻茎秆倒伏指数,归因于弯矩力矩显著降低及折断弯矩显著提高,渝香203变幅较大。一方面,烯效唑处理通过缩短基部节间长度,进而降低株高和重心高,使得弯曲力矩降低;节间形态建成期内源GA1+3和IAA含量减少,使得细胞长度和长宽比降低,是基部节间长度缩短的重要原因。另一方面,烯效唑提高了内源Z+ZR和IP+IPA含量,细胞变小且排列致密,机械组织细胞层数和维管束鞘细胞数量增加,使得大、小维管束数目和面积、机械组织厚度增大,进而提高了茎秆折断弯矩。相关分析表明,细胞长度、细胞长宽比、机械组织厚度和大、小维管束面积与倒伏指数显著负相关,与折断弯矩显著正相关,两品种趋势一致。【结论】遮阴下,烯效唑通过降低内源生长素和赤霉素,使得基部节间长度缩短,提高内源细胞分裂素,减小细胞大小和长宽比,增加细胞致密程度,机械组织细胞层数和维管束鞘细胞数目,大、小维管束数目和面积、机械组织厚度相应增加,从而改善了弱光胁迫下杂交籼稻茎秆机械强度和抗倒伏性。

干旱胁迫对紫叶紫薇容器苗生长及生理的影响

为探究干旱胁迫对紫叶紫薇容器苗的生长及生理影响,以紫叶紫薇优良新品种‘丹红紫叶’2年生容器苗为研究对象,设计了5个干旱胁迫强度处理,测定不同干旱胁迫处理对容器苗生长及生理相关指标的影响。结果表明:干旱胁迫对紫叶紫薇容器苗的生长及生理的影响显著。随着干旱胁迫强度增加,紫叶紫薇容器苗叶片相对含水量、过氧化物酶活性、超氧化物歧化酶活性、可溶性蛋白含量、净光合速率、气孔导度、蒸腾速率总体上呈现降低趋势,重度干旱时这些指标分别比正常供水显著下降了21.45%、40.45%、31.92%、3.30%、81.25%、89.29%、87.17%,极重度干旱时达到最低值。可溶性糖含量、脯氨酸含量、丙二醛含量随着干旱胁迫程度增强而一直上升,重度干旱时分别比正常供水显著增加了122.92%、74.98%、288.34%,极重度干旱时达到最大值。随着干旱胁迫强度加重,过氧化氢酶活性、叶绿素相对含量、水分利用效率呈现先升高后降低的趋势,中度干旱时过氧化氢酶活性最大,叶绿素相对含量和水分利用效率则是轻度干旱最高,极重度干旱时最低。胞间CO_(2)浓度随着干旱胁迫加强而先降后升,正常供水的胞间CO_(2)浓度最高,中度干旱最低。紫叶紫薇容器苗具有抵御中度干旱的能力,当土壤相对含水量下降至30%~35%时应及时给苗木浇水灌溉。

华南籼稻骨干亲本稻瘟病基因检测与抗性评价

选用Pi2、Piz-t、Pi9、Pi25、Pi5、Pita、Pia、Ptr、Pi1、Pikm、Pi54等11个抗稻瘟病基因的功能性分子标记,对华南稻区近年育成的90个籼稻骨干亲本进行抗性基因鉴定与稻瘟病抗性评价。结果表明,综合抗性等级达到高抗、抗、中抗、中感、感及高感的亲本分别为0份、3份、35份、38份、14份和0份,且年度间表现较为一致。不同鉴定时期的稻瘟病抗性级别相关性分析进一步显示,苗瘟与叶瘟、苗瘟与穗颈瘟以及叶瘟与穗颈瘟的抗性级别呈极显著正相关。对上述11个抗性基因在90个亲本中的分布进行检测,发现除Pi9基因以外,其他10个抗性基因在亲本中的分布频率分别为75.56%(Pi54)、70.0%(Pi5)、47.78%(Pi2)、31.11%(Pi25和Pia)、20.0%(Ptr)、15.56%(Pi1)、13.32%(Pita)、4.44%(Pikm)和1.11%(Piz-t)。11个抗性基因在不同省际间育成亲本中的分布频率差异较大。进一步结果表明,随着聚合抗性基因数量的增加,亲本抗性水平呈相应提升趋势,但不同抗性基因组合对于提升水稻亲本抗病性的贡献呈现明显差异。本研究为华南稻区新育成籼型常规水稻品种的合理布局及抗稻瘟病基因的育种应用提供有益的参考。

育苗容器对紫叶紫薇容器苗生长、开花及生理的影响

【目的】探讨育苗容器类型和规格对紫叶紫薇容器苗生长、开花及生理的影响,筛选出培育紫叶紫薇容器苗的适宜育苗容器,为高效培育紫薇容器苗提供理论依据。【方法】以紫叶紫薇优良新品种‘丹红紫叶’2年生苗木为研究材料,选用黑色塑料营养杯(C1)、白色无纺布美植袋(C2)、黑色控根容器(C3)3个类型以及16×16(D1)、21×21(D2)、25×25(D3)3种规格(直径×高,cm),组成9种容器组合处理,测定不同处理容器苗生长、开花及生理指标。【结果】(1)不同育苗容器处理对紫叶紫薇容器苗的生长、开花及生理指标均影响显著,同一容器类型苗木的生长、根系、生物量、花期、花径、花序、可溶性蛋白含量、可溶性糖含量、相对叶绿素含量、净光合速率、气孔导度、蒸腾速率等指标均随着育苗容器规格的增大而显著增加。(2)地径生长量、总根长、总根表面积、总根体积、根尖数、地上部干质量、地下部干质量、总干质量、花期均以C3D3处理最大,比最小的C1D1处理分别显著提高817.12%、108.12%、94.60%、75.66%、144.14%、135.67%、228.45%、164.65%、34.48%;苗高生长量、冠幅生长量、叶面积、花序长和宽均以C1D3处理最高,比最低的C1D1处理分别显著提高116.05%、81.39%、114.95%、70.44%和65.79%;相对叶绿素含量、水分利用效率均以C3D3处理最大,可溶性蛋白和可溶性糖含量、净光合速率、气孔导度均以C1D3处理最高;胞间CO_(2)浓度、水分利用效率在各处理之间无显著差异。(3)各处理隶属函数法综合评价得分排序为:C3D3>C1D3>C2D3>C3D2>C2D2>C1D2>C2D1>C3D1>C1D1。【结论】黑色控根容器在地径生长量、根系生长指标、生物量、花期和花径、叶绿素相对含量及净光合速率方面表现最佳;紫叶紫薇2年生苗的最适宜育苗容器是直径25 cm、高25 cm的黑色控根容器。

南繁基地牛筋草对草甘膦的抗药性研究

牛筋草是一年生禾本科恶性杂草,在我国黄淮海流域及长江以南地区的农田危害严重。草甘膦是一种优良的非选择性除草剂,随着生物育种产业化的推进,草甘膦会逐步在玉米、大豆等作物田登记应用。育种基地抗草甘膦杂草的产生是其快速传播的潜在因素。为明确三亚一育种基地牛筋草种群对草甘膦的敏感性,本研究利用生物测定、分子生物学等方法检测了待测种群的抗性水平,并分析了可能的分子机制。结果发现,草甘膦对牛筋草种群的生长抑制中量为2053.0 g/hm^(2)(有效成分用量),抗性指数(RI)为5.0;靶标基因EPSPS的保守区域无突变,但相对表达量是敏感种群的47.4倍;抗性植株中EPSPS蛋白的浓度是敏感植株的17.1倍。以上结果表明,该牛筋草种群对草甘膦产生了中等水平抗性,靶标基因过量表达是其抗性机制之一。

淹水胁迫对紫薇苗生长及生理特性的影响

以紫薇优良新品种‘丹红紫叶’二年生苗为试材,采用套盆淹水方法,设计了5个淹水持续时间处理,研究不同淹水胁迫处理对紫薇苗生长及生理指标的影响,以期为紫薇苗培育及园林应用的水分管理提供参考依据。结果表明:紫薇能承受14 d的淹水,淹水21 d是紫薇忍受淹水胁迫持续时间的极限。随着淹水胁迫时间增长,紫薇苗的叶片相对含水量、过氧化物酶活性、超氧化物歧化酶活性、可溶性蛋白质含量、净光合作用速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr)、胞间CO_(2)浓度(Ci)均总体呈下降趋势,淹水21 d时分别比对照处理显著下降了24.29%、79.88%、18.66%、3.16%、80.45%、92.51%、93.10%、25.43%,淹水28 d时达到最低值;脯氨酸、丙二醛含量呈上升趋势,淹水21 d时分别比对照显著增加67.34%、360.54%,淹水28 d最大;过氧化氢酶活性呈先升后降的趋势,淹水21 d最大,比对照显著增加252.65%;可溶性糖含量呈先降后升再降的趋势,淹水21 d最大,比对照显著增加19.38%;淹水胁迫期间紫薇苗的叶绿素相对含量变化不明显;水分利用效率(WUE)呈起伏波动走势,对照最低,淹水21 d较高,比对照显著高184.00%。紫薇苗具有一定的耐涝性,淹水胁迫持续时间不宜超过14 d。

牛筋草PFK蛋白多克隆抗体的制备及其在草甘膦抗性鉴定上的应用

抗草甘膦牛筋草中磷酸果糖激酶(PFK)与靶标酶5-烯醇式丙酮酰莽草酸-3-磷酸合酶(EPSPS)的含量存在线性关系,是牛筋草对草甘膦产生抗性的指示蛋白之一。为实现抗草甘膦牛筋草的快速鉴定,本研究克隆了牛筋草PFK全长基因,构建原核表达载体,并免疫大兔最终获得多克隆抗体,进一步对抗体的特异性和灵敏性进行了检测,并用该抗体对抗性牛筋草进行了检测鉴定。结果发现,PFK基因全长1656 bp,编码551个氨基酸,该基因的原核表达载体pGEX-4T-1-PFK经诱导后表达的蛋白大小为45 kD,蛋白纯化后浓度为3.5 mg/mL。制备的多克隆抗体能特异地识别牛筋草PFK蛋白,稀释512000倍后仍可检测到抗原,并能够准确鉴定PFK不同表达量的抗性牛筋草。结果表明:本研究制备的PFK多克隆抗体具有特异性强、灵敏度高的特点,可鉴定EPSPS过表达的抗草甘膦牛筋草,这为牛筋草对草甘膦抗药性的快速鉴定提供了实用工具。

部标1级优质稻新品种黄丝粤占的选育

在保障粮食安全和消费者对稻米品质要求日益提高的双重背景下,为了培育高产、优质、广适性大品种,笔者在核心种质育种理论指导下,通过将传统系谱法、分子标记辅助选择技术和运用先进仪器设备鉴定相结合的方法,选育出部标(NY/T 83—2017)1级优质稻新品种黄丝粤占。黄丝粤占在不同年度和不同区域试验中表现出株型理想、丰产性好、适应性广、抗稻瘟病、食味品质优异的特性,实现了高产、优质和抗病等优良基因的有效聚合。2023年黄丝粤占通过广东省农作物品种审定委员会审定,适宜广东粤北以外稻作区作早、晚稻种植,具有很大的推广潜力。