Effect of Extreme Natural High Temperature on Seed Setting Rate of Rice(Oryza sativa L.) at Heading and Flowering Stage

The seed setting rates of total 198 rice cultivars （lines） at heading and flowering stage were investigated under the condition of extreme natural high tem- perature in 2013 so as to analyze the effect of extreme natural high temperature on seed setting rate of different rice cultivar （line）. The results showed that the contin- uous high temperature showed certain effects on the seed setting rates of tested materials, and significant differences were shown in seed setting rate among differ- ent rice cultivars （lines）. The seed setting rates differed significantly among indica F1 hybrids derived from different sterile and restorer lines, indicating that the sterile and restorer lines had great effects on heat tolerances of different F~ hybrids. The cor- relation analysis showed that the seed setting rates of conventional indica restorer lines and conventional japonica rice cultivars （lines） were negatively related to the daily highest temperature （P〉0.05）, and the seed setting rates of indica F1 hybrids were positively related to the seed setting rates of their restorer lines. Total four in- dica restorer lines, including Ninghuiguangkangzhan, Shuhui 527, Chenghui 3203 and Xianyin-8, and four new japonica rice cultivars （lines）, including Wuyinjinghui （B2）, Nanjing 4//W3660/Nanjing 44 （B12） and Wuyun 2330/JD6011 （B22） were pre- liminarily screened, and their seed setting rates were all close to the normal level （90%）. The screened rice cultivars （lines） showed higher heat tolerances.

Research Progress on Heat Stress of Rice at Flowering Stage

Global warming has caused frequent occurrence of heat stress at the flowering stage of single-season rice in the Yangtze River region of China, which results in declines of spikelet fertility and yield in rice. Rice flowering stage is the most sensitive period to high temperatures, and therefore, the key for heat stress happening is the flowering stage coinciding with high temperature, which causes spikelet fertility decreasing in heat-sensitive varieties, and is the major factor for heat injury differences among various rice planting regions. With the development of rice breeding, temperature indexes for heat stress has been converted from daily maximum temperature of 35 oC to 38 oC with the stress duration of more than 3 d. During the flowering stage, anther dehiscence inhibition and low pollen shedding onto the stigma are two main reasons for spikelet fertility reduction under high temperatures. At panicle initiation stage, high temperatures aggravate spikelet degeneration, and destroy floral organ development. Various types of rice varieties coexist in production, and indica-japonica hybrid rice demonstrates the highest heat resistance in general, followed by indica and japonica rice varieties. In production, avoiding high temperature is the main strategy of preventing heat stress, and planting suitable cultivars and adjustment of sowing date are the most effective measures. Irrigation is an effective real-time cultivation measure to decline the canopy temperature during the rice flowering stage. We suggested that further study should be focused on exploring heat injury differences among different rice variety types, and innovating rice-planting methods according to planting system changes in rice planting regions with extreme heat stress. Meanwhile, high temperature monitor and warning systems should be improved to achieve optimal heat stress management efficiencies.

Separation and Identification of Stage-specific Proteins in Pistillate Flowers of Mulberry

In order to excavate the function genes of stage-specific proteins in the development process of mulberry pistillate flowers, using fruit mulberry cuhivar ＇ Da 10＇ as experiment material, two-dimensional electrophoresis and mass-spectrometric technology were used to investigate specifically expressed proteins of mul- berry pistillate flowers in different flowering periods. The results showed that 471 ± 4,450 ± 15 and 446 ± 14 protein spots were determined in mulberry pistil- late flowers at full-bloom stage, initial flowering stage and terminal flowering stage respectively, including nine protein spots with characteristics of stage-specific ex- pression and clear electrophoretic bands.. By mass spectrometry analysis, database retrieval and bioinformatics analysis, five components were successfully identi- fied as lactoylglutathione lyase-like protein, perchloric acid soluble translation inhibitor protein, ubiquitin-conjugating enzyme 1 like protein, putative ethylene re- sponse protein and 3-hydroxyisobutyrate dehychngenase, which were involved in stress resistance reaction, protein catabolism, signal transduction, glycometabolism and other biological processes in plants, which indicated that these proteins might play an important biological function in the normal development and pollination fertilization of mulberry pistillate flowers.

Drought Tolerance Identification and Eevluation of Maize during Flowering Stage in Guangxi

Total 20 maize varieties were subjected to drought stress at flowering stage,and then the relative water content,soluble sugar content,chlorophyll content,malondialdehyde( MDA) content and superoxide dismutase( SOD) activity in their leaves,as well as their yields were determined. The drought tolerance of the physiological and biochemical indexes was scored by five-level scoring method,and the drought tolerance index was calculated by the yield index to comprehensively evaluate the drought tolerance of maize during flowering stage. The results showed that the scores of drought tolerance of the maize varieties ranged from 1. 929 3 to 5. 659 5. Among them,the scores of Zhengda 619,Guidan 162 and Guidan 0810 were greater than 5. 0,followed by Dika 008,Xianyu 30 T60,Xianzhengda 901,Qingnong 68,South America No. 1 and Wanchuan 1306 of which the scores were in the range of 4. 0-5. 0. The drought tolerance indexes were in the range of 0. 410 4-1. 096 3. Among the test maize varieties,the drought tolerance indexes of Guidan 0810,Pacific 99 and Zhengda 619 were greater than 1. 0,and those of Xianyu 30 T60,Dika 008 and South America No. 1 were in the range of 0. 9-1. 0. The correlation between the two kinds of evaluation results was 0. 588 7 and was extremely significant. The five-level scoring method and the drought tolerance index can be used simultaneously for the evaluation of drought tolerance of maize during flowering stage. The two aspects of evaluation results showed that Guidan 0810,Zhengda 619,Xianyu 30 T60,Dika 008 and South America No. 1 were drought-tolerant varieties,among which Guidan 0810 and Zhengda 619 were extremely highly drought-tolerant varieties.

Analysis of Meteorological Disasters in the Flowering and Fruiting Period of Sugar Orange in Guilin

The yield of sugar orange is closely related to meteorological conditions in the flowering and fruiting period, and meteorological disasters at the flowering and early fruiting stage seriously affect its yield. To study influences of meteorological disasters in the flowering and early fruiting stage on sugar orange industry in Guilin, meteorological disasters in the flowering and early fruiting stage and its defense measures were analyzed and studied. The flowering and early fruiting stage of sug- ar orange in Guilin is from March to June, and sudden change of temperature, thunderstorm, hale, hail, rainstorm and other natural disasters can cause the falling of large numbers of flowers and young fruit, damage of tree body, reduction of fruit in quantity, and decrease of its yield. Timely understanding information of disastrous weather and implementing management of water and fertilizer can effectively reduce the loss caused by meteorological disasters and ensue high quality and high yield of sugar orange.

Performance of Three Adelphocoris spp.(Hemiptera: Miridae) on Flowering and Non-flowering Cotton and Alfalfa

The genus Adelphocoris（Hemiptera： Miridae） is a group of key insect pests in cotton fields in China that includes three dominant species： A. suturalis（Jakovlev）, A. lineolatus（Goeze） and A. fasciaticollis（Reuter）. Previous field surveys have found that adults of these Adelphocoris species usually move onto specific host plants when the plants enter the flowering stage. To determine the potential trade-offs for this host-plant preference behavior, the performance of these three Adelphocoris spp. on flowering and non-flowering cotton and alfalfa were compared in the laboratory. The results showed that Adelphocoris spp. had significantly higher nymphal developmental and survival rates, along with increased adult longevity and fecundity on flowering cotton and alfalfa than on non-flowering plants of either species. In addition, compared with cotton plants, alfalfa generally promoted better performance of these three Adelphocoris species, especially for A. lineolatus. Simple correlation analysis indicated that female adult longevity was positively correlated to male adult longevity and female fecundity, and female fecundity was positively correlated to nymphal development and survival rates. This study demonstrated a positive correlation between adult preference and offspring/adult performance for all three Adelphocoris species, with no evidence of any trade-offs for this preference for flowering host plants. These findings support the hypothesis that hemimetabolous insects such as mirid bugs have positive adult preference-adult/nymphal performance relationships, which is likely due to the similar feeding habits and nutritional requirements of adults and nymphs.

The Effect of Low Temperature and High Temperature on Flowering and Pollination of Red Cartridge Kiwifruit in Western Guizhou in Early Spring of 2021

Based on the daily average temperature from March 19 to April 2,2021 at three surface meteorological stations in western Guizhou and the daily average temperature,maximum temperature and minimum temperature from March 19 to April 2,2021 at 12 main automatic meteorological stations of red cartridge kiwifruit base,the effects of low temperature and high temperature on flowering and pollination of red cartridge kiwifruit in early spring of 2021 were analyzed.The results showed that slight cold spell in later spring in western Guizhou occurred from March 21 to 23.The lower limit of the daily average temperature required for flowering period(12℃or below)appeared in each base of red cartridge kiwifruit during March 21-23,which affected the red cartridge kiwifruit trees in Faer,Houchang,Miluo,Shunchang,Panlong and Jichang bases flowering and pollinating before March 20.From March 29 to April 2,the daily maximum temperature of Faer and other eleven bases was 30℃or above,which caused the wilting and abscission of flowers and young fruits of of red cartridge kiwifruit trees in Faer,Houchang,Miluo,Shunchang,Panlong,shaomi,Jichang and Aga bases blooming and pollinating before March 24,but the flowers of red cartridge kiwifruit trees in Langdai,Longhe,Pugu and Shuangfeng bases blooming and pollinating after March 28 were not damaged.

Optimum harvesting time of herbaceous peony buds for cutting flowers

The herbaceous peony is one of the cut flowers that has become increasingly popular in the international market in recent years. In the study, 11 cultivars of herbaceous peonies suitable for cutting flowers were selected; different harvesting stages （three or four stages） were identified according to bud development observation （bud firmness, bud diameter, sepal angle, petal angle, and color showing）. Moreover, flower development and vase life were also recorded in the experiment of vase. Bud development observation shows that there are great differences in optimum harvesting stage between the culti- vars, especially between the hybrid peony group and lactiflora group. This implies that bud diameter could not be the only indicator for optimum harvesting stage. Bud description, including sepal opening angle, sepal color, petal color showing, and degree of firmness, is necessary for the determination of the harvesting stage. Among the 11 cultivars,‘Pink Hawaiian Coral＇, ‘Red Charm＇, ‘Edulis Superba＇, ‘Red Magic＇, and ‘Sarah Bernhardt＇ should be harvested at stage 1. ‘Duchesse de Nemours＇, ‘Taff＇, ‘Sorbet＇ and ‘Monsieur Jules Elie＇ should be harvested at stage 2. ‘Kansas＇ should be at stage 3 and ‘Karl Rosenfield＇ at stage 4. The determination of optimum harvesting stage for each cultivar is an important element in cut flower production.

Evaluation on Climate Suitability in Main Growth Stages of Zhaotong Apple in Recent 60 Years

Based on daily average temperature,precipitation and sunshine hours during 1961-2018 from two meteorological stations of Zhaoyang District and Ludian County at Zhaolubazi,Zhaotong City,Yunnan Province,using the freezing injury index at flowering stage(Ha),climatic suitability index during expansion period(Pa),climatic suitability index during coloring period(Dy)and climatic suitability index during fruit growing period(Si),etc.,the climatic suitability of Zhaotong apple during the main growth stages was evaluated.The results showed that the annual average temperature was 11.8-12.3℃at Zhaolu Bazi in recent 60 years,and the climate was the most suitable for Fuji apple planting both in the south and north;the average annual precipitation was 674.8-852.6 mm,and the climate was suitable in the north and sub-suitable in the south;the annual average sunshine hours was between 1845.4 and 1851.1 h,and the climate was sub-suitable in both areas.The Ha was between 0.42-0.50,serious in the north and moderate in the south;the Pa was between 0.92 and 1.02,and both the south and the north were suitable areas;the Dy was between 0.95 and 1.00,and the climate in the south was suitable,while it was sub-suitable in the north;the Si was between 1.38 and 1.59,and the climate was suitable in the south and sub-suitable in the north.There was a 4-year cycle in the interannual variation of Ha,Pa,Dy and Si.After the 1980s,the Ha decreased by 0.56-0.59,the Pa,Dy and Si respectively increased by 0.10-0.16,0.14-0.15 and 0.78-0.84 with the temperature rise,and the changes of these four indexes were all favorable for Fuji apple's fruits growth.It can be seen that under the background of the global warming,the climatic conditions in Zhaolu Bazi are becoming more and more favorable for popularizing the planting of Fuji apple.

Coordinated Expression of Cytosolic and Chloroplastic Glutamine Synthetase During Reproductive Stage and Its Impact in GS1 RNAi Transgenic Rice

To understand the reallocation of organic nitrogen from leaf to the flower head of rice, the role of glutamine synthetase （GS） was investigated by characterizing GS1 RNAi transgenic rice, which revealed a significant reduction in panicle number and number of seeds per panicle. We observed the expression of GS isotypes at transcriptional and protein levels in flag leaves, leaf sheaths and panicles at three different flower development stages. The mRNA expression of GS1;1 was clearly suppressed in flag leaves, especially at the flowering stage. GS1 protein was barely detectable in flag leaves until the flowering stage, while GS1 protein was compromised in the leaf sheath and panicle, with transient expression of GS2 protein at the flowering stage. The glutamine level in transgenic plants was significantly reduced in both flag leaves and panicles, but ammonium was highly accumulated. The level of other amino acids, including aspartate and asparagine, tended to be higher in RNAi transgenic plants than the wild type plants during the reproductive stage. In addition, accumulation of toxic ammonium in panicles with low glutamine level might have caused low seed-setting in the transgenic rice. These results indicated that nitrogen reallocation was critical for panicle development, and that multiple GS isotypes functioned cooperatively to complete the rice life cycle when leaf nitrogen was remobilized to the developing reproductive organs.

Phenological stage effect on phenolic composition and repellent potential of Mentha pulegium against Tribolium castaneum and Lasioderma serricorne

Objective:To elucidate for the first time the phenological stage effect on polyphenol,flavonoid and proanthocyanidin contents of pennyroyal(Mentha pulegium)as well as their antioxidant capacities and insecticidal potentials against Tribolium castaneum and Lasioderma serricorne.Methods:Crude methanol extracts from pennyroyal(Mentha pulegium)aerial parts were evaluated for their anti radical,reducing power activities and repellent potentials against selected coleopteran insects during different phenological stages.Results:Phenolic contents of pennyroyal aerial parts and their antioxidant effects were significantly dependent on maturity stage of the plant.The maximum of phenol production was reached during the full flowering stage.Apigenin was the major phenol in Mentha pulegium with an amount of6.01 mg/g of dry vegetable matter during this period.Nevertheless,at fructification stage,the highest antioxidant activity was not related to high phenolic content.The repulsive effect of pennyroyal extract showed that Lasioderma serricorne was more susceptible to pennyroyal extract than Tribolium castarneum with corresponding median repellent dose values of 0.124and 0.006 mg/mL respectively.Moreover,great differences in insect repulsion depending on extract concentrations,exposure time and developmental stage was observed.For the lowest concentration(0.125 mg/mL),the repellent effect against Tribolium reached its maximum(90%)during the fructification stage(after 24 h of exposure)while this repellent effect was 80%during the vegetative stage.Conclusions:Due to the strong insecticidal potential of pennyroyal extracts,this study highlights the therapeutic properties of this plant and encourages its use as a safer,environmental-friendly and efficient insecticide in food industry.

玉米花粉高温胁迫相关miRNA的筛选及其靶基因分析

以高耐热玉米品种郑单958、低耐热玉米品种先玉335为材料,以正常生长条件为对照,在花期进行高温胁迫,通过miRNA高通量测序筛选玉米花粉中的差异表达miRNA,然后预测其靶基因,并对靶基因的本体特征和代谢通路进行富集分析。结果表明,共筛选到818个miRNA前体序列。在郑单958高温胁迫花粉与对照花粉对比组(HT958 vs CK958)中共筛选到19个显著差异表达miRNA序列,其中15个miRNA序列上调表达,4个下调表达,3个miRNA序列达到极显著水平(P<0.01)。对这19个显著差异表达miRNA的靶基因进行预测,共获得了503个基因转录本,其富集较多的GO生物学过程条目分别为转录调控DNA-模板、微管生物学过程、磷酸化作用、RNA聚合酶Ⅱ正向调控转录过程、甲基化作用等,KEGG富集较显著的代谢通路分别是谷胱甘肽代谢、碳代谢、花生四烯酸代谢、糖酵解/糖异生、叶酸生物合成等。在先玉335高温胁迫花粉与对照花粉对比组(HT335 vs CK335)中共筛选到15个显著差异表达miRNA序列,其中7个miRNA序列上调表达,8个下调表达,1个miRNA序列达到了极显著水平(P<0.01)。对这15个显著差异表达miRNA的靶基因进行预测,共获得了454个基因转录本,其富集较多的GO生物学过程条目分别为转录调控DNA-模板、磷酸化作用、蛋白质磷酸化作用、蛋白质水解、DNA修复等,富集较显著的KEGG代谢通路分别是其他多糖降解、亚油酸代谢、代谢通路、硫胺素代谢、内质网内蛋白质加工过程等。在郑单958高温胁迫花粉与先玉335高温胁迫花粉对比组(HT985 vs HT335)中共筛选到85个显著差异表达miRNA序列,其中35个miRNA序列为上调表达,50个为下调表达,24个miRNA序列达到了极显著水平(P<0.01)。对这85个显著差异表达miRNA的靶基因进行预测,共获得了2 286个基因转录本,其富集较多的GO生物学过程条目分别为转录调控DNA-模板、磷酸化作用、蛋白质磷酸化、蛋白质水解、跨膜转运等,富集较显著的代谢通路分别是鞘脂类代谢、淀粉和蔗糖代谢、其他多糖降解、代谢通路、半胱氨酸及甲硫氨酸代谢等。在HT958 vs CK958与HT335 vs CK335对比组中共筛选到94个显著差异表达miRNA序列,其中(预测全新)PC-3p-10069_1143、(预测全新)PC-3p-18335_646、(玉米)zma-miR164f-5p等28个miRNA序列达到了极显著水平(P<0.01)。对这94个显著差异表达miRNA的靶基因进行预测,共获得了4 569个基因转录本,其富集较多的GO生物学过程条目分别为转录调控DNA-模板、磷酸化作用、蛋白质磷酸化、蛋白质转运、蛋白质水解等,其富集较显著的KEGG代谢通路分别是内质网内蛋白质加工过程、真核生物核糖体生物合成、剪接体、鞘脂类代谢、内吞作用等。

外源GA_(3)对“白雪塔”牡丹花期生理效应的影响

以观赏牡丹“白雪塔”为试材,采用植株喷施法,研究了外源赤霉素(GA_(3))对牡丹花期生理效应的影响,以期为牡丹产业中的催花调控、切花生产及旅游创收等方面提供参考依据。结果表明:外施500 mg·L-1GA_(3)可使“白雪塔”提前4~5 d开花且花期延长2~3 d,有效拓宽了观赏花期。同时还显著降低了幼叶和花瓣内脱落酸(ABA)含量,提高了GA_(3)、生长素(IAA)含量及IAA/ABA、GA_(3)/ABA、(IAA+GA_(3))/ABA比值。低含量的ABA和高比值的(IAA+GA_(3))/ABA是“白雪塔”花期延长的重要内部激素调控因素。此外,外施GA_(3)还显著降低了花期衰老进程中的超氧阴离子(O·2)产生速率和丙二醛(MDA)含量,提高了可溶性蛋白质含量及超氧化物歧化酶(SOD)活性。与各自对照相比,幼叶内可溶性蛋白质含量和SOD活性分别比对照提高了39.3%~118.2%、20.7%~38.3%;花瓣可溶性蛋白质含量和SOD活性则分别提高了43.0%~60.3%、23.9%~57.0%(P<0.05)。可溶性蛋白质含量及SOD活性的提高,有效缓解了因开花衰老诱发的过量活性氧对细胞膜脂造成的过氧化伤害,在抑制初花至败花期时的组织衰老方面,发挥了重要的防御作用。

冷水灌溉对水稻扬花期遭受短时高温危害的缓解效果

以灌溉水的温度处理(冷水初始温度20.0℃、常温水初始温度27.7℃)为主区,以气温处理(高温38.0℃、自然气温32.0℃)为副区,进行裂区实验设计,开展田间实验,探索高温与自然气温下水稻体温的变化特征及冷水灌溉和常温水灌溉对水稻剑叶、穗及节间温度的影响规律。结果表明:与自然气温相比,高温条件下水稻剑叶、穗及节间温度分别显著提高5.9℃、5.7℃和0.9℃。高温条件下使用两种温度的水灌溉时,冷水灌溉(LHT)处理的水温升高更快、升温幅度更大,10:00-15:00升温幅度达6.0℃;而常温水灌溉的水温变化缓慢,从10:00的27.7℃升至15:00的30.0℃,升温仅2.3℃。可见,高温条件下灌溉冷水比常温水吸收更多的热量。因此,高温条件下,与常温水灌溉处理相比,冷水灌溉处理使水稻剑叶、穗及节间温度显著降低了1.5℃、1.3℃和1.6℃,增大了气-叶温差、气-穗温差及气-节间温差。高温条件下,冷水灌溉能有效降低水稻体温,起到良好的避热效果,因此可以考虑作为缓解高温热害的一种技术手段。

单季稻开花结实期高温热害特征及防控对策

近年,长江流域稻区单季稻开花结实期高温频发重发。本文分析了高温年水稻开花结实期高温热害特征及高温对结实率的影响。高温年日最高温度高,持续时间延长;高温年7月上旬至8月上旬日最高温度较常温年高4.3℃~4.8℃;水稻开花结实期遇到高温热害结实率下降28.2~43.4个百分点;品种间耐高温热害特性差异较大。根据开花结实期高温热害特征及高温引起结实率下降的特点,提出高温预警及播期调整、耐热品种选择、高温期间田间灌水、喷施生长调节物质等开花结实期高温热害防控对策。

长江中下游地区糯玉米花期耐热性鉴定及评价指标筛选

全球气候变暖趋势日趋明显,高温热害已成为限制糯玉米丰产稳产的主要非生物胁迫之一。鉴定糯玉米的耐热性,筛选耐高温评价指标,可为耐热糯玉米品种的选育提供理论支撑。本研究以长江中下游地区主推品种为试验材料,设置2种增温方式(覆膜增温处理和延迟播种处理)以及自然对照处理(CK),测定了13个与耐热相关的指标,采用主成分分析、隶属函数法、聚类分析和逐步回归分析相结合的方法,对糯玉米花期耐热性进行综合评价。结果显示,与对照相比,除叶绿素a和光系统II最大光化学效率外,各指标在高温处理下的降低幅度均达到显著或极显著水平。利用主成分分析将13个单项指标转换为3个相互独立的综合指标,其贡献率分别为64.46%、15.06%和7.76%,代表了糯玉米耐热性87.28%的原始数据信息量;通过隶属函数计算综合耐热评价值(D值),将10个参试糯玉米品种划分为3类,分别为3个耐热型、4个中等耐热型和3个热敏感型。筛选出的耐热型品种为苏玉糯2号、中糯2号和苏玉糯901,生产中应用这些品种可能在一定程度上减轻高温热害对糯玉米生长发育造成的不利影响。最后,利用逐步回归分析建立了糯玉米耐热性评价方程预测供试材料的耐热性,预测值(PV)与D值基本一致,确定了产量、F_v/F_m、叶面积指数和花粉活力作为糯玉米花期耐热性评价指标。本研究筛选出的耐热品种和鉴定指标可为今后耐热糯玉米品种的选育提供理论依据。

基于主成分-聚类分析芝麻盛花期耐高温评价及品种筛选

【目的】明确芝麻盛花期高温胁迫对植株农艺性状、产量及其构成因素和籽粒品质的影响,精确评价不同芝麻品种在盛花期的耐高温水平,筛选耐高温芝麻品种。【方法】以24份芝麻品种作为试验材料,设置常温对照(CK)和盛花期高温胁迫(H)2个处理,盛花期高温处理7 d,于成熟期取样进行考种,测定株高、始蒴部位、单株蒴果数、每蒴粒数、千粒重、单株产量等农艺性状指标,并测定其含水量、含油量和蛋白质含量等品质指标。运用主成分分析和聚类分析方法,综合分析评价不同芝麻品种盛花期的耐热性。【结果】不同的品种、温度处理及互作对芝麻的各项指标均具有显著影响。盛花期高温胁迫后,芝麻的单株产量、千粒重、单株蒴果数、每蒴粒数、始蒴部位、果轴长度和株高分别较对照(CK)下降了33.47%、13.62%、7.76%、5.75%、2.61%、1.64%和1.40%,其中,千粒重和单株产量下降幅度最大,差异均达显著水平;黄稍尖和蛋白质含量分别较对照(CK)下降了13.43%和1.55%,差异不显著。含水量和含油量分别较对照(CK)增加了0.90%和0.17%,差异不显著;不同品种和各项指标的耐高温系数之间存在着一定的相关性,将农艺性状及籽粒品质等11个指标的耐高温系数进行主成分分析,建立5个相互独立的综合指标,贡献率分别为30.74%、25.82%、13.18%、10.12%和8.33%,反映了88.19%的原始信息。通过成分矩阵和特征值计算各指标的权重,构建出高温胁迫生理综合指标模型(HTSPCI)。根据各单项指标的耐高温系数进行聚类热图分析,将24个品种划分为4个等级,分别为耐高温型、中度耐高温型、中度热敏感型和热敏感型;6个耐高温型品种单株产量损失率X6≤9.50%;6个中度耐高温型品种的单株产量损失率为9.50%70%。【结论】盛花期高温胁迫显著影响芝麻的生长发育。采用主成分-聚类分析将植株的农艺性状指标与品质指标相结合,构建高温胁迫综合指标模型,筛选出6个耐高温品种,可用于评价不同芝麻品种耐高温程度。

台湾连蕊茶不同花期及花器官挥发性成分分析

采用固相微萃取-气相色谱-质谱联用(SPME-GC-MS)技术,对台湾连蕊茶(Camellia lutchuensis T.Ito)不同花期及花器官的挥发性成分及其相对含量进行分析。结果表明:台湾连蕊茶不同花期和花器官的主要挥发性成分均为醇类。台湾连蕊茶5个花期(包括蕾初期、蕾后期、半开期、盛花期和衰败期)花器官的挥发性成分分别有42、38、33、37和28种,其中芳樟醇和苯乙醇的相对含量总体较高,为主要香气成分。在花开放过程中,芳樟醇相对含量呈先降低后升高的变化趋势,在蕾初期最高(61.27%);苯乙醇相对含量呈先升高后降低的变化趋势,在半开期最高(59.40%)。花瓣和雄蕊的挥发性成分分别有32和43种,其中花瓣中芳樟醇相对含量最高(32.95%),雄蕊中苯乙醇相对含量最高(48.55%)。综上所述,台湾连蕊茶花器官主要香气成分为醇类中的芳樟醇和苯乙醇。

盐肤木开花特性及花香成分释放规律分析

【目的】探究盐肤木开花特性和花香成分及其释放规律,为进一步开发利用盐肤木花香提供依据。【方法】用扫描电镜观察花粉形态,用顶空-固相微萃取(HS-SPME)与气相色谱联用(GC-MS)技术检测分析不同花期主要花香成分和日变化规律。【结果】盐肤木雌雄异株,圆锥花序,单枝花序集中开花,整株持续开花,花粉黄色,长球形具3孔沟,外壁具条纹。不同花期检测出花香物质共92种(萜烯类29种,醛类19种,酯类15种,醇类14种,酮类5种,烯烃类4种,芳香烃类2种,酚类、烷烃类、酸类和其他类各1种)。其相对含量先升高后降低,在盛花期时达到最大(3.60μg/g),各花期间差异显著,种类持续增加。其盛花期共检测到84种花香物质,释放量日变化呈抛物线趋势,白天显著高于夜晚,18:00时达到最大(4.80μg/g),后持续降低,6:00时最低,仅2.58μg/g。其中萜烯类为盐肤木主要花香物质,相对含量约占总花香含量的70%。【结论】盐肤木花香成分丰富,具明显昼夜节律变化,萜烯类为其主要花香物质。

薄壳山核桃主栽品种花期观察及品种配置

对薄壳山核桃〔Carya illinoinensis(Wangenh.)K.Koch〕8个主栽品种的花期以及8个主栽品种和12个开花结实表现较好的品种的雌花可授期和雄花散粉期进行观察,确定品种配置方案。结果显示:薄壳山核桃8个主栽品种的花期基本在4月中下旬至5月中上旬。‘波尼’(‘Pawnee’)的初花期最早,‘金华’(‘Jinhua’)的初花期最晚。‘马罕’(‘Mahan’)的终花期最早,‘金华’的终花期最晚。‘波尼’和‘卡多’(‘Caddo’)雌花的盛花期持续时间为15 d,其余6个主栽品种雌花和雄花的盛花期持续5~9 d。‘波尼’、‘卡多’、‘曼丹’(‘Mandan’)和‘苏普锐尔’(‘Surprize’)的可授期持续11~14 d。总体上看,‘波尼’和‘卡多’的可授期与其余主栽品种的散粉期重叠,且二者的散粉期与其余主栽品种的可授期重叠。‘金华’的可授期与‘马罕’、‘绍兴’(‘Shaoxing’)、‘威奇塔’(‘Wichita’)、‘斯图尔特’(‘Stuart’)和‘特贾斯’(‘Tejas’)的散粉期重叠。8个主栽品种的散粉期持续5~7 d,其中,‘波尼’的散粉期最早开始,‘金华’的散粉期最晚开始。‘金华’、‘威奇塔’、‘斯图尔特’、‘特贾斯’、‘曼丹’和‘苏普锐尔’可以作为‘波尼’和‘卡多’的授粉树,‘波尼’、‘卡多’、‘曼丹’和‘苏普锐尔’可以作为‘马罕’、‘绍兴’、‘威奇塔’、‘斯图尔特’和‘特贾斯’的授粉树。