花生抗旱指标研究初报

用干旱棚分别在正常供水与水分胁迫条件下，研究了抗旱性不同的4个花生品种叶片相对含水量，失水率，萎蔫指数，株高，根冠比，座果率的变化与品种抗旱性的关系，并用隶属函数进行抗旱性综合分析，结果表明，4个花生品种各项抗旱性生理及形态指标的变化与抗旱指数的相关性次序是：根冠比＞叶片蒸蔫指数＞叶片失水率＞叶片相对含水量＞座果率＞株高，品种综合抗旱性强弱为：远杂9307＞远杂9102＞豫花6号＞白沙1016，因此本项研究为花生抗旱品种的选育提供了科学依据。     

甜瓜种质资源苗期抗旱性生理鉴定指标测定

以6个甜瓜品种为试材,测定其株高胁迫指数(PHSI)、干物质胁迫指数(DMSI)、叶片水分饱和亏(WSD)、相对含水量(RWC)、束缚水含量、组织水含量、自由水含量、电解质渗出率、干旱处理伤害率、离体叶片抗脱水能力等指标,并对各指标进行显著性测验,评价各品种的抗旱性。结果表明:鉴定甜瓜品种抗旱性,苗期可应用株高胁迫指数(PHSI)、干物质胁迫指数(DMSI)、叶片水分饱和亏、电解质渗出率、干旱处理伤害率等指标。     

干旱胁迫对赤芍生理特性影响及相关基因的克隆表达

为探究不同干旱程度对赤芍生长发育的影响及其抗旱机制,采用盆栽控水法,设置对照组、轻度干旱和重度干旱3个处理,测定赤芍叶片相对含水量、可溶性糖、可溶性蛋白、脱落酸、叶绿素、类胡萝卜素、类黄酮、丙二醛、游离脯氨酸含量、光合参数及超氧化物酶活性等生理指标,评价赤芍抗旱性;采用RT-PCR结合RACE技术克隆抗旱相关基因（DREB、Psb27、PsaK、MDHAR、SOD和GR）,探究不同干旱程度对赤芍相关基因表达水平的影响。结果表明,重度干旱胁迫下,赤芍可溶性糖、可溶性蛋白、类胡萝卜素、类黄酮、脯氨酸、丙二醛、抗坏血酸及谷胱甘肽的含量均呈上升趋势,如在重度干旱和轻度干旱24 d后,赤芍叶片可溶性糖含量分别为对照的2.50倍和1.66倍,重度干旱胁迫第16天时,可溶性蛋白含量为对照组的2.43倍,类胡萝卜素与类黄酮的含量分别约为对照组的1.8倍和1.4倍,约为轻度干旱的1.4倍和1.2倍;而叶片相对含水量、蒸腾速率、气孔导度、净光合速率与叶绿素含量均降低,如重度干旱胁迫下赤芍叶片含水量不足20%,而轻度干旱和对照组叶片含水量均高于55%,叶绿素含量在第16天降到最低值,约为对照组的26%,为轻度干旱的33%;干旱胁迫下,光合作用相关基因Psb27、PsaK的表达量上调,且重度干旱上调水平更高;多个抗氧化基因的表达量（SOD、GR）、ABA含量以及胞间CO₂浓度呈先升后降趋势,如SOD在重度干旱第16天表达水平达到峰值,分别为轻度干旱与对照组的1.58倍和1.86倍,而后剧烈下降,到第24天时表达水平降到对照组的1.43倍,其中MDHAR的表达量呈下降趋势,重度干旱第24天时表达水平降到对照组的5.53倍。     

不同品种马铃薯叶片生理特性与抗旱性研究

在水分胁迫条件下,对马铃薯可溶性糖含量、高体叶片失水速率及叶片含水量与品种抗旱性关系的研究结果表明:马铃薯叶片可溶性糖含量的相对值与品种抗旱性呈极显著的正相关(r为0.9768,P＜0.01),离体叶片失水速率的相对值与品种抗旱性呈显著的负相关(r=-0.925,P＜0.05),叶片含水量的相对值与品种抗旱性呈显著的负相关(r=-0.8844,P＜0.05),上述三项指标均可用于马铃薯不同品种抗旱性评价.     

棉花抗旱相关指标综合评价及灰色关联分析

以30份棉花资源为材料,在大田对棉花花铃期进行干旱胁迫,于胁迫第10天测定光合指标,并分别取样测定叶片丙二醛（MDA）、叶绿素（Chl a+b）、超氧化物歧化酶（SOD）、脯氨酸（Pro）等的变化,吐絮后测定农艺性状;同时采用抗旱系数、抗旱指数、灰色关联分析等相结合的方法,对棉花的抗旱性进行综合评价。根据抗旱性度量值（D值）聚类分析结果,将30份材料聚类为4个类型,高抗旱型品种有贝尔斯诺、川98、库克C310-5100、KK1543、中R2015;中等抗旱型品种有新陆早49、新陆中8号、中R773-1等13个品种;抗旱型品种有新陆早47、辽18、富依德998等8个品种;干旱敏感型品种有军棉1号、中R2009、新陆早26、新陆中58。通过灰色关联分析,16个指标与D值的紧密程度依次为有效铃数、总铃数、有效果枝数、Gs、Tr、果枝数、MDA、叶绿素总量、Pn、叶绿素b、株高、WUE、叶绿素a、Pro、Ci、SOD。在受到干旱胁迫时,棉花农艺性状表型指标敏感,同时MDA、叶绿素总量这2个指标反应较其它生理生化指标敏感,蒸腾速率（Tr）、气孔导度（Gs）、净光合速率（Pn）相对其它光合指标较敏感。     

水稻川香29B近等基因导入系苗期根系形态、叶片生理生化特性与抗旱性的关系

为减少材料遗传背景差异，快速鉴定水稻抗旱性和筛选鉴定指标，以籼稻川香29B近等基因系及其轮回亲本川香29B为研究对象，在温室内于苗期采用反复干旱法进行干旱胁迫，测定苗期物质变化、形态指标、根系和叶片生理生化指标，分析各指标与抗旱性的关系，并通过相关分析和回归分析筛选抗旱鉴定指标。结果表明：苗期反复干旱胁迫导致6份供试材料根系干物质积累量和根冠比分别增加25.59%、45.60%（P＜0.05），叶片中类胡萝卜素、丙二醛、脱落酸和乙烯含量的平均值分别提高29.17%、6.03%、25.25%、40.74%（P＜0.05），可溶性蛋白质含量平均值提高9.77%，叶片中过氧化物酶、超氧化物歧化酶、过氧化氢酶、吡咯碄-5-羧酸合成酶、鸟氨酸转氨酶和脯氨酸脱氢酶活性的平均值分别增加11.81%、37.43%、25.91%、32.65%、31.46%、29.07%（P＜0.05），地上部干物质积累量、叶片SPAD值、叶绿素a含量、叶绿素b含量、叶片生长素、细胞分裂素、赤霉素的平均值分别下降14.22%、9.00%、18.79%、55.32%、31.04%、19.29%、34.79%（P＜0.05）；川香29B/ASOMINORI//川香29B///川香29B（C1）的第1次干旱存活率、第2次干旱存活率和反复干旱存活率分别为90.86%、82.86%、86.86%，均为最高，川香29B/ASOMINORI//川香29B///川香29B（C3）和川香29B/ASOMINORI//川香29B///川香29B////川香29B（C4）的反复干旱存活率分别为71.51%、72.72%，均显著低于其他4份材料。相关分析和逐步回归表明，根表面积、总根长及叶片还原性谷胱甘肽含量、过氧化物酶活的相对值可作为水稻苗期抗旱性鉴定指标。苗期反复干旱存活率可直接鉴定水稻苗期抗旱性。基于反复干旱存活率，川香29B/ASOMINORI//川香29B///川香29B（C1）苗期抗旱性最强。     

干旱胁迫对藜麦幼苗生长和叶绿素 荧光特性的影响

以甘肃省农业科学院自育品种陇藜1号（L-1）、2号（L-2）、3号（L-3）和4号（L-4）及外引品种白藜（BL）幼苗为试验材料,采用盆栽人工控水法,共设置轻度干旱胁迫（LD,土壤含水量为田间持水量的50%~60%）、中度干旱胁迫（MD,土壤含水量为田间持水量的30%~40%）和重度干旱胁迫（SD,土壤含水量为田间持水量的10%~20%）3个水分梯度,以正常浇水为对照（CK,土壤含水量为田间持水量的70%~80%）,干旱胁迫15 d后,通过测定幼苗株高、根长、生物量及叶片叶绿素含量、初始荧光（Fo）、最大荧光（Fm）、PSⅡ最大光化学效率（Fv/Fm）、PSⅡ潜在活性（Fv/Fo）及非光化学猝灭系数（NPQ）,研究干旱胁迫对藜麦幼苗生长和叶绿素荧光特性的影响。结果表明：（1）随干旱胁迫程度的加剧,参试藜麦品种幼苗株高、地上部分鲜重和地上部分干重呈逐渐降低的变化趋势,SD处理下,各供试品种株高分别降低了30.64%、28.36%、32.67%、37.88%和38.09%,地上部分鲜重分别下降了63.60%、6073%、59.74%、55.92%和61.74%,地上部分干重分别下降了62.96%、52.63%、29.41%、35.71%和60.00%;（2）5个藜麦品种幼苗叶片叶绿素a、叶绿素b、总叶绿素及叶绿素a/b随着干旱胁迫程度的加剧而呈现先升高后降低的趋势,SD处理下,品种L-2、L-3和L-4叶绿素a分别比CK降低了28.48%、33.66%和17.99%,叶绿素b分别比CK降低了47.80%、45.08%和13.90%,总叶绿素含量分别比CK降低了33.22%、36.20%和15.99%;（3）随干旱胁迫程度的加剧,各供试藜麦品种Fo、Fm、Fv/Fm和Fv/Fo均呈下降趋势,SD处理下,各供试品种Fo分别较CK下降了30.61%、14.56%、31.28%、24.39%、24.16%,Fm下降了19.11%、16.56%、16.76%、17.67%、22.19%,Fv/Fm分别下降了5.73%、4.29%、7.81%、4.58%和3.85%,Fv/Fo分别下降了19.40%、14.93%、24.02%、11.34%和12.11%;（4）5个供试品种叶片NPQ随干旱胁迫程度的加剧呈升高趋势,SD处理下,各供试品种NPQ较CK升高了74.79%、161.54%、104.55%、200.00%和196.00%。综上所述说明中度和重度干旱胁迫下,植物细胞失水,叶绿体遭到破坏,光合作用降低,叶绿素合成受到抑制,光合产物减少,从而抑制幼苗生长,地上部分生物量下降。在幼苗生长和叶绿素荧光特性等方面,藜麦品种L-2表现优于其他品种,表明其在干旱胁迫下较其他供试品种具有更强的适应能力。     

干旱胁迫下两种芽胞杆菌对玉米幼苗促生作用研究

供试玉米品种为‘先玉335’（XY335）,供试菌株为NECC11322(Bacillus subtilis)枯草芽胞杆菌、NECC11324(B. megaterium)巨大芽胞杆菌。试验设4组处理：Con（无菌水浸种,干旱胁迫）,C1（无菌水浸种,正常供水）,C2（NECC11322菌液浸种,干旱胁迫）,C3（NECC11324菌液浸种,干旱胁迫）,测定了浸种后盆栽玉米幼苗的生长状况、抗性生理指标及植株的N、P、K含量。结果表明：在干旱胁迫下接种NECC11322、NECC11324后,玉米幼苗叶片及根系SOD、POD、CAT、APX活性较Con均不同程度升高,其中接种NECC11322根系POD活性增长最为显著,较Con增长67.78%;植株叶片及根系可溶性蛋白含量、可溶性糖含量较Con均呈上升趋势,其中接种NECC11322叶片可溶性糖含量增长最为显著,较Con增长152.10%;与Con相比,植株叶片及根系全氮、全磷、全钾养分含量均有所提升,接种NECC11322后叶片全氮含量升高最为显著,较Con增长88.47%;干旱胁迫下接种两种芽胞杆菌后,植株叶片及根系丙二醛含量较Con均显著降低,接种NECC11322[JP2]后根系降幅最为显著,较Con降低51.03%。综上可知,干旱胁迫下接种两种芽胞杆菌均可降低干旱胁迫对玉米幼苗生长的抑制,其中NECC11322菌株更具有抗旱性。通过提高保护酶活性、可溶性蛋白、可溶性糖含量、叶绿素含量以及植株养分含量提高玉米幼苗抗旱性,促进玉米幼苗生长。     

干旱胁迫对3种苹果属植物叶片解剖结构、微形态特征及叶绿体超微结构的影响

采用树脂包埋块半薄/超薄切片技术，通过光镜（LM）、扫描电镜（SEM）和透射电镜（TEM）方法，研究了轻度、中度和严重干旱胁迫对楸子（Malus prunifolia）、新疆野苹果（M. sieversii）和平邑甜茶（M. hupehensis）叶片组织解剖结构、表皮微形态特征（气孔密度、大小及角质层厚度）及叶绿体超微结构的影响。光镜观察结果表明，与对照相比，干旱胁迫条件下3种苹果属植物叶片厚度、栅栏组织厚度及叶肉组织结构紧密度（CTR）都显著减小（P＜0.05），而海绵组织厚度与叶肉组织结构疏松度（SR）均显著增加（P＜0.05）。扫描电镜观察结果显示，3种苹果属植物幼叶气孔密度在干旱胁迫下显著增大（P＜0.05），而气孔宽度、开张比及其开张度明显下降。透射电镜观察结果表明，在干旱胁迫下，楸子和新疆野苹果上下角质层厚度逐渐增加，而平邑甜茶的随干旱胁迫程度增加呈先增后减的变化；在轻度和中度水分胁迫下，叶绿体膨胀变形，淀粉粒变小消失，基粒片层排列松散减少，类囊体腔扩大；在严重胁迫条件下，叶绿体膨胀近圆形，叶绿体膜破裂，类囊体严重泡化开始解体。与平邑甜茶相比，严重水分胁迫下楸子和新疆野苹果叶绿体超微结构损伤较小，能较好地保持细胞结构的完整性。     

两种水分条件下真菌接种及氮肥施加对小麦生长、生理及氮磷吸收的影响

为探究不同水分条件下真菌接种和氮肥施加对小麦生长、水分利用效率及营养吸收的影响,以小麦品种Superb为材料,选取丛枝菌根接种（接种和不接种）和氮肥施加（0 kg·hm^-2和180 kg·hm^-2）在两个水分处理（拔节期开始,水分充足95%（WW）和水分胁迫40%田间持水量（WD））的温室条件下进行试验,分析开花期生长及叶片气体交换参数和成熟期产量及籽粒、茎秆氮磷含量的变化,最后对水分利用效率和籽粒、茎秆氮磷含量作了相关性分析。结果显示：两种水分条件下接种丛枝菌根（AMF）均显著提高旗叶的比叶面积（SLA）,其中,水分胁迫处理施氮显著降低叶片SLA,AMF接种显著增大叶片的相对含水量（RWC）;两种水分条件下,菌根接种和氮肥（N）施加均显著提高叶片净光合速率（Pn）和蒸腾速率（Tr）,其中,水分胁迫处理下,AMF接种对Pn的影响显著,N肥施加和AMF接种后的Pn比CK高31%;两种水分处理下,N肥施加和AMF接种后小麦WUE和瞬时水分利用效率（WUEi）值升高,其中,水分胁迫环境下,AMF接种和N肥施加下小麦WUE分别提高了13.02%和1.17%,且不同处理下叶片稳定性碳同位素分辨率（CID）也有所升高。水分胁迫处理下,施N和AMF接种均显著提高小麦茎和籽粒氮含量、株高、生物量和产量,茎秆和籽粒的磷含量也显著升高。WUE与籽粒、茎秆氮、磷含量呈显著的正相关,CID与籽粒、茎秆氮磷含量呈显著负相关关系。总的来说,N肥施加和AMF接种可显著改善小麦在干旱条件下的生长及生理变化。     

Temperature requirements for germination,germ tube growth and appressorium formation of urediospores of Hemileia vastatrix

Requirements for germination, germ tube growth and appressorium formation of urediospores ofHemileia vastatrix, the causal organism of coffee leaf rust, were investigated by applying treatments with constant temperatures, ranging from 10 to 31°C, and with variable temperatures. Observations were made after 4, 6, 8 and 24 h of incubation of the spores in distilled water on glass slides. The lower and upper limits for germination were estimated to be 13 and about 30°C, respectively. Germination was quickest at 22 to 28°C, whereas appressoria formed more rapidly at 13 to 16°C. After 24 h of incubation, a broad optimum, from 16 to 28°C, was observed for germinationn and total appressorium formation. The shape of the appressoria was torpedo-like or roundish at 13 to 19°C, whereas at higher temperatures their shape was predominantly irregular. Germ tube length increased linearly with time, with an optimum at 19 to 22°C. The degree of branching of the germ tube was positively correlated with germ tube length. Germination percentage and appressorium formation were higher on leaf disks than on glass slides. With variable temperatures, significant correlation were found between temperature sum and percentage of germination, appressorium formation and germ tube length.The results show that germination and appressorium formation can occur at lower temperatures than reported in literature. Penetration byH. vastatrix seems te be realized most rapidly in nature, if, after wetting of the spores, a decline in temperature occurs from initially ca. 23 to 17°C within a few hours. Such conditions prevail during evening and early night in many areas where Arabica coffee is grown.Samenvatting De temperatuurbehoeften voor kieming en appressoriumvorming van uredosporen vanHemileia vastatrix werden onderzocht door incubatie bij constante temperaturen, 10 tot 31°C, en variabele temperaturen. Waarnemingen werden gedaan na 4, 6, 8 en 24 uur incubatie van de sporen in gedestilleerd water op glasplaatjes. De onder- en bovengrens voor kieming bleek bij 13 en ca 30°C te liggen. De kieming kwam het snelst op gang bij 22 tot 28°C en de appressoriumvorming bij 13 tot 16°C. Na 24 uur incubatie werd een breed optimum waargenomen van 16 tot 28°C voor het kiempercentage en het totale aantal appressoria. De vorm van de appressoria was torpedoachtig of rond bij 13 tot 19°C, terwijl bij hogere temperaturen de vorm meestal onregelmatig was. De lengte van de kiembuis nam vrijwel rechtlijnig toe met de tijd, met een optimum van 19 tot 22°C. De vertakkingsgraad van de kiembuizen was positief gecorreleerd met de kiembuislengte.Kieming en appressoriumvorming verliepen beter op de bladschijven dan op glasplaatjes. Bij de behandelingen met variabele temperaturen werden significante correlaties waargenomen tussen de temperatuursom en de kiembuislengte en ook tussen de temperatuursom en het kiem- en appressoriumpercentage.De resultaten tonen aan dat kieming en vooral appressoriumvorming bij lagere temperaturen kan plaatsvinden dan verondersteld in de literatuur. Ze suggereren dat penetratie vanH. vastatrix het snelst gerealiseerd kan worden in de natuur als, na bevochtiging van de sporen, een temperatuurdaling plaatsvindt van aanvankeljk ca. 23 naar ca. 17°C binnen een paar uur. Deze conditie komt veelvuldig voor in de namiddag en het begin van de nacht in vele gebieden waar Arabica-koffie wordt verbouwd.     

Development of an effective screening method for partial resistance to Alternaria brassicicola (dark leaf spot) in Brassica rapa

In order to develop a method to measure resistance to Alternaria brassicicola (cause of dark leaf spot disease) in Brassica rapa, the effects of inoculum concentration, leaf stage, leaf age and incubation temperature of inoculation on infection were studied under controlled conditions using several B. rapa genotypes. Three inoculation methods (cotyledon, detached leaf and seedling inoculation) were evaluated for this purpose. The detached leaf inoculation test was the most suitable for screening B. rapa genotypes because clear symptoms were observed on the leaves in less than 24 h, and there was a significant positive correlation between the results from the detached leaf inoculation test and the seedling inoculation test, an established method considered to yield reliable results. In addition, it was very easy to screen plants for resistance on a large scale and to maintain standard physical conditions using detached leaves. For successful infection, inoculum concentration should be adjusted to 5 × 10⁴ conidia ml⁻¹, and incubation temperature should be between 20 °C and 25 °C. The 3rd/4th true leaves from 30 day-old plants were optimal for inoculation. In a screening test using 52 cultivars of B. rapa, the detached leaf test effectively discriminated between various levels of partial resistance among cultivars. As a result, we identified two cultivars, viz Saori and Edononatsu, as highly resistant and five cultivars, viz Tokinashi Taisai, Yajima Kabu, Purara, Norin-F₁-Bekana and Tateiwa Kabu, as having borderline resistance.     

水稻细菌性条斑病发生及流行因子分析

人工接种及病区调查研究结果表明，在种植感病品种情况下，气温决定了水稻细菌性条斑病的发生与否和潜育期的和短衣病斑长度；病害发生的最低温为１２℃，发病最适温度为２５－３０℃以上，而湿度决定此病发病率及严重度。结合主成分分析，该病在田间的流行取决于温度／湿度及降雨量。台风暴雨造成的伤口有利于病害的流行。     

柑桔潜叶蛾的耐寒力和对嫩叶含水量的敏感性测定

在实验室条件下系统地测定了柑桔潜叶蛾的耐寒力和幼虫对嫩叶含水量的敏感性。结果表明,１－２龄幼虫对低温最敏感,其次是卵,蛹耐寒力最强,其次是３－４龄幼虫,当温度≤１５℃时,１－２龄幼虫的死亡率随着温度的降低和低温持续时间延长而增加;当温度≤１０℃时,温度越低,持续时间越长,３－４龄幼虫和蛹的死亡率越高,卵的孵化率越低。     

Factors affecting the incubation period of dark leaf and pod spot (Alternaria brassicae) on oilseed rape (Brassica napus)

Experiments to investigate the factors affecting the incubation period of dark leaf and pod spot (Alternaria brassicae) on leaves and pods of oilseed rape (Brassica napus) were done in controlled environment (constant temperatures) and glasshouse conditions (fluctuating temperatures). The length of the incubation period of dark leaf and pod spot decreased as infection and incubation temperatures increased from 6 to 20 °C. The incubation period decreased as wetness period increased from 2 to 12 h, as inoculum concentration increased from 80 to 2 × 10³ spores ml^–1 and as leaf age increased from 4 to 10 days. Asymptotes of leaf age and inoculum concentration, above which the length of the incubation period did not decrease, were 10 days and 2 × 10³ spores ml^–1, respectively. The shortest and longest incubation periods were 1 and 11 days. The mechanism by which the infection conditions influenced the incubation period of dark leaf and pod spot on oilseed rape seemed to be linked to lesion density. Usually, the length of the incubation period decreased greatly with increasing lesion density.     

Environmental conditions influencing Sclerotinia sclerotiorum infection and disease development in lettuce

The environmental factors that influence infection of lettuce by ascospores of Sclerotinia sclerotiorum , and subsequent disease development, were investigated in controlled environment and field conditions. When lettuce plants were inoculated with a suspension of ascospores in water or with dry ascospores and exposed to a range of wetness durations or relative humidities at different temperatures, all plants developed disease but there was no relationship between leaf wetness duration or humidity and percentage of diseased plants. Ascospores started to germinate on lettuce leaves after 2–4 h of continuous leaf wetness at optimum temperatures of 15–25°C. The rate of development of sclerotinia disease and the final percentage of plants affected after 50 days were greatest at 16–27°C, with disease symptoms first observed 7–9 days after inoculation, and maximum final disease levels of 96%. At lower temperatures, 8–11°C, disease was first observed 20–26 days after inoculation, with maximum final disease levels of 10%. Disease symptoms were always observed first at the stem base. In field-grown lettuce in Norfolk, 2000 and 2001, inoculated with ascospore suspensions, disease occurred only in lettuce planted in May and June, with a range of 20–49% of plants with disease by 8 weeks after inoculation. In naturally infected field-grown lettuce in Cheshire, 2000, disease occurred mainly in lettuce planted throughout May, with a maximum of 31% lettuce diseased within one planting, but subsequent plantings had little (≤ 4%) or no disease. Lack of disease in the later plantings in both Norfolk and Cheshire could not be attributed to differences in weather factors.     

不同生态型小麦春播条件下幼穗分化进程与温度和叶片出生的关系

研究了不同生态型小麦在春季分期播种条件下的幼穗分化进程与温度和叶片出生的关系。结果表明,随播期后移,春型小麦幼穗分化历时缩短,所需积温相对稳定。冬型小麦则历时延长,但是所需积温增加;小麦品种冬性越强,幼穗分化历时越长,所需积温越多。小麦叶龄与幼穗分化的对应关系因生态型而异。冬性小麦幼穗分化各个时期对应的叶龄均高于春性小麦;不同生态型小麦幼穗分化同一时期内经历的叶片数目不尽相同。     

膜下滴灌棉花叶温变化规律及其与气象因素关系的研究

通过对新疆石河子市148团膜下滴灌棉花灌区实验地各行棉花叶片温度及土壤含水率的测定、各行棉花发育情况的调查和当地气象资料的收集,利用Origin7．5的函数拟合功能,分析了棉花叶温与当地气象资料的关系。并且分析了棉花叶温与土壤含水率和棉花生长发育情况的关系,以便讨论在本研究种植模式下如何提高棉花产量。结果表明：棉花叶温与气象因素的相关性从高到低排列顺序依次为气温、空气饱和水汽压差、空气相对湿度、日照时数、风速。其中,棉花叶温与气温的相关系数为0．91327,其拟合方程可以用来预测棉花叶片温度。另外,棉花叶片的温度会随土壤含水率的增高而降低,在本研究“一膜两管,一管三行”,“66＋10”的种植模式下,棉花叶片温度较低的那行生长发育情况较好,且产量也较高。建议在本研究种植模式下将中行棉花适当向滴灌管附近移动,以此来提高棉花产量。     

科尔沁沙地不同环境条件下植物叶凋落物CO2释放研究

采用可以有效控制环境因子的室内土壤培养试验,对不同生境土壤、土壤水分及温度作用下叶凋落物释放CO2的情况进行了初步研究。结果表明:①在培养的前4 d,土壤水分含量越高,叶凋落物释放CO2的速率越快;而从整个培养期来看,沙地中较低的含水量对叶凋落物释放CO2的速率无显著的影响。②在流动沙地和半流动沙地的生境中,凋落物释放CO2的总量高于丘间低地和固定沙地。③叶凋落物释放CO2速率与环境温度呈显著的正相关(F=0.7316,P<0.01)。在10℃,20℃以及30℃条件下,CO2的释放速率均较为平稳,而在40℃时0~16 d呈现出明显逐步加快的趋势,在17~24 d则缓缓下降并趋于平稳。     

冬小麦叶片形状系数的变异性

研究了2014-10—2015-06生长季内6个不同熟性冬小麦品种全生育期内叶片形状系数的变化规律,将小麦生育期划分为出苗、返青、拔节、抽穗、开花、成熟等6个不同生长阶段,依次采样计算各个阶段的α均值,同时考虑α值在单个植株不同叶片之间的差异,以及不同冬小麦品种之间的差异。结果表明:α值总体在0.59到0.71之间,随冬小麦生育期的变化而变化,自苗期到开花期波动增大,开花后缓慢下降;在单个植株之内,α值变异性较大,开花期最为稳定,开花后变异性增加;不同熟性冬小麦品种之间,α值在拔节、抽穗和开花期表现出显著差异,而在出苗、返青和成熟期,差异不显著。因此,建议最好在不同的作物生长阶段采用不同的叶片性状系数,以提高叶面积模拟和预测精度。对全生育期3种熟性6个冬小麦品种的1 485个叶片的面积和长宽乘积进行线性回归分析,可知总体的冬小麦叶片形状系数值约为0.66。以叶面积模型LA=0.66×L×W来估算冬小麦叶片面积,其总体的相对均方根误差(RRMSE)约为4.40%,绝对相对误差(absolute relative error,ARE)约为13.05%,在5种不同叶面积估算模型中精度最高,因此推荐该模型用于估算田间小麦叶片面积。