亚低温对不同品种薄皮甜瓜生理特性的影响

为筛选出耐低温品种,以4个甜瓜品种‘羊角脆’、‘八棱脆酥瓜’、‘黄皮香瓜’、‘黑皮酥’为试验材料,利用人工气候箱控温,研究了亚低温对甜瓜幼苗生长及叶片生理特性的影响。结果表明:甜瓜的生理生化指标如叶绿素含量、硝酸还原酶、抗坏血酸过氧化物酶、电解质渗漏率、根系活力、SOD、CAT、APX活性影响甜瓜的生长发育,可作为评价甜瓜抗寒性的可靠指标。综合比较四个品种的甜瓜在经过亚低温胁迫后各项生理指标及形态指标,耐寒性强弱排序为‘黑皮酥黄皮香瓜羊角脆八棱脆酥瓜’。因此,在江淮地区种植甜瓜时,‘黑皮酥’更能适应低温寒冷天气,而‘八棱脆酥瓜’的耐寒性最弱。     

不同品种苜蓿对低温胁迫的生理响应及抗寒性评价

研究选取不同品种的苜蓿作为研究对象,进行低温胁迫。通过进行丙二醛含量、超氧化物歧化酶、过氧化物酶、游离脯氨酸含量、叶绿素含量、相对电导率等与抗寒性密切相关指标分析各品种的相对抗寒能力。结果表明:低温胁迫使不同品种苜蓿的游离脯氨酸含量、超氧化物歧化酶、过氧化物酶、丙二醛、相对电导率等指标增加,而叶绿素相对含量与对照比较有不同程度的下降,综合多项指标评价得出黄花苜蓿、草原二号、俄罗斯杂花苜蓿、龙苜806抗寒能力较强。其中,黄花苜蓿抗寒能力明显优于其它品种。     

河南省主推小麦品种越冬期生理生化特性比较研究

田间自然条件下,在小麦越冬期对百农矮抗58、郑麦9023、周麦18、周麦22、郑麦7698、豫麦49的叶片和分蘖节取样,测定与抗寒性相关的生理生化指标.结果表明:与其他品种相比,百农矮抗58分蘖节和叶片中的可溶性糖、可溶性蛋白以及游离脯氨酸含量,POD活性整体高于郑麦9023、周麦18、周麦22、郑麦7698、豫麦49,相对电导率低于郑麦9023、周麦18、周麦22、郑麦7698、豫麦49.说明百农矮抗58的抗寒性较好,这些特点为其高产、稳产、广适奠定了生理基础;同时,百农矮抗58可溶性糖、电导率、脯氨酸含量变化规律较强,可以作为辅助鉴定半冬性小麦品种抗寒性的生理指标.     

低温对白菜型冬油菜幼苗叶绿素荧光启动过程与品种抗寒性的影响

分析低温对叶绿素荧光启动过程与品种抗寒性的影响,筛选建立准确和无伤害的白菜型冬油菜抗寒性鉴定指标和方法.在-6℃低温条件下,应用调制荧光仪测定6个具有抗寒性差异的白菜型冬油菜品种幼苗叶片叶绿素荧光启动过程,采用相关性和主成分分析综合评价低温对白菜型冬油菜幼苗叶片叶绿素荧光启动与品种抗寒性的影响.结果表明:在低温下,不同品种间白菜型冬油菜幼苗叶片叶绿素荧光启动过程中各荧光参数存在较大差异;相关性及主成分分析的结果表明,各荧光参数间存在密切的相关性,叶绿素荧光参数Fs,φPSIIR,NPQ,ETR、Fm'和Fo'可用于白菜型冬油菜幼苗抗寒性准确、无伤害的鉴定指标,其中Fs、φPSIIR、Fm'为最敏感的指标;低温下,白菜型冬油菜幼苗叶片叶绿素荧光启动越快,品种抗寒性越强;Fs下降并到达稳定状态的时间越短,Fm'降幅越小,φPSIIR越大,品种越抗寒.     

聚乙二醇处理对烟草种子活力及幼苗抗寒生理的影响

用聚乙二醇(PEG)处理烟草种子,测定PEG对种子活力的影响,筛选活力最强?种子培养幼苗至4叶期,在5℃下分别胁迫1-5 d,测定烟草抗寒性相关生理生化指标。结果显示:处理组烟苗的叶绿素含量、可溶性蛋白含量和保护酶过氧化物酶(POD)、过氧化氢酶(CAT)、超氧化歧化酶(SOD)活性均高于对照组;超氧阴离子(O-2)含量低于对照组。表明PEG浸种处理能提高烟草种子活力和幼苗的抗寒性。     

低温胁迫对珙桐幼苗的抗寒性生理生化指标的影响

为探明低温胁迫对珙桐(Davidiainvolucrata)抗寒性相关生理指标的变化规律,分别在4℃,8℃低温条件下对珙桐幼苗叶片内过氧化物酶(POD)活性、叶绿素和游离脯氨酸含量的变化进行了研究.结果表明:随着温度降低珙桐叶片内叶绿素含量和POD活性呈现下降的趋势;脯氨酸随着胁迫的进行其含量升高,表明叶片内脯氨酸的升高也有助于提高它的抗寒性,进一步可以认为叶片内脯氨酸含量的高低可作为衡量珙桐抗寒性指标.     

寒胁迫对冬小麦拔节期叶片游离脯氨酸含量的影响

0～4℃低温处理冬小麦拔节期抗寒性不同的品种,随处理时间延长,叶片中游离脯氨酸含量增加,抗寒性强的品种游离脯氨酸的积累较多．表明植物抗寒性与叶片中游离脯氨酸积累有相关性．     

山西南部油橄榄引种驯化研究

本试验对山西南部油橄榄的引种驯化进行了研究。实验测定了引入的油橄榄品种的抗寒性相关指标丙二醛和脯氨酸的含量,选出抗性品种。结果表明:山西南部引种地的气候条件大体适合油橄榄的生长,气温是主要限制因子;实验所测的6个品种(鄂植八号、配多灵、佛奥、莱星、阿斯、皮削利)中,佛奥、鄂植八号、莱星3个品种丙二醛含量低而脯氨酸含量高,抗寒性强,是优先引入品种,其中鄂植八号最为适合;配多灵、皮削利、阿斯3个品种丙二醛含量高而脯氨酸含量低,抗寒性差,不利于山西南部引种。     

不同土壤条件对曼地亚红豆杉抗寒性影响研究

以不同土壤(酸壤和碱壤)条件下3年生曼地亚红豆杉为材料,用生理生化方法从低温半致死温度(LT50)、自由水和束缚水含量2项生理指标研究了曼地亚红豆杉在自然降温过程中抗寒力的变化,所得各项结果分别为:(1)不同土壤条件的曼地亚红豆杉低温半致死温度在自然降温过程中均随着气温的降低而降低,且与采样前半月平均最低温度呈线性相关,在整个变化过程中,二者的低温半致死温度均表现为:酸性土壤小于碱性土壤.(2)酸性土壤条件下束缚水含量和束缚水与自由水比值均明显高于碱性土壤条件下.最后确定了曼地亚红豆杉抗寒性大小为:酸性土壤强于碱性土壤.     

寒胁迫对小麦幼苗生理生化特性的影响

:0～ 4℃低温处理小麦幼苗 ,叶片中脯氨酸和可溶性蛋白含量大幅度提高 .不同小麦品种可溶性糖含量也有不同程度的增加 .抗寒性强的品种 ,3种物质积累较多     

卡思卡特城堡

It is worthy of noting that, whilst Crookston Castle witnessed the earlier and happier portion of Mary's variegated life,     

不同的吃喝玩乐

一、吃和喝吃苹果 eat an apple, 吃药 take medicine,吃糖 have some sweets,吃饭 have one's meals,吃馆子 dine out,吃惊 be surprised/     

漏洞百出的教育

Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help?     

Western and Eastern culture differences in commercial field

The communication of people partially is the communication of cultures. Culture has a direct effect on international commercial activities in all aspects. Different conceptions about time, space, equality, law and the like, lead people to deal with things in different ways. So to know cultures of the counterpart is to facil-itate our enterprises so as to have a smooth and successful communication in commercial activity.     

只要努力,不要后悔

There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love.     

浅谈移民问题

Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject.     

Sister Carrie, an Adherent of Desires

Sister Carrie is one of the most controversial characters in American literature.Thought as a "fallen woman" firstly,she was defined as a "new woman" by some critics later. However, by digging into the motivaton behind the whole process of Carrie's "success", the relationship between Carrie and her creator (the author), the social conditions of then American, it can be found that Carrie has never been free-standing on her thought and she has never found her real-sdf even after becoming a famous actress. In a society dominated by mass consumerism Carrie is only an adherent of her own desires. She also is a representative of all those country girls flooded into cities, a symbol and a sacrifice of the urbanization of America in a time countryside was overcome by cities.     

Improvement of one-cycle controller by use of proportional integral differential controller

1.IntroductionOne-cyclecontrolmethod,whichwasproposedaboutonedecadeago[1],hasbecomeanattractivemethodinspecialfieldssuchaspowerfactorcorrection[2-6],switchingamplifiers[7,8],etc.Themainideaofthiscontrollerisbasedonintegrationofdiodevoltageinone-cycleandforcesittobeexactlyequaltothereferencevalue.Themainadvantageofthiscontrollerisitsrealtimeabilitytorejectthevariationofinputvoltage[1].Despitethisgreatability,ithasnogoodperformancesinrejectingofloaddisturbanceandfollowingreferencecommands.Espec…     

风的曲线

Rosco and I wait for the fishermen to return.I sit at a wooden bench near the store at Mt.Baker Resort and watch the clouds change shape. Rosco has my belt around his neck and an eight foot tow chain hooked to a tree. Dogs must be on a leash. Ducks and rabbits are loose.