基质和炼苗方法对春石斛试管苗假植的影响     

刘洪科  ;许震寰  ;文颖  ;邹宗兰  ;钟雨薇 《甘蔗(福建)》2008,(4):306-310

以4个品种的春石斛为材料,研究了不同的假植基质和不同的炼苗时间和方法对春石斛试管苗假植成活率和初始生长的影响。结果表明,所涉及的基质中,水苔的成活率最高,而炼苗方法以封瓶炼10 d再开瓶炼1 d最佳。  相似文献   

水稻籽粒灌浆特性及品质对孕穗期     

刘奇华  蔡建  李天  张建军 《江西农业大学学报》2007,29(2):172-175

以3个不同直链淀粉含量的水稻品种为材料,研究了孕穗期弱光对水稻籽粒灌浆及稻米品质的影响,并用Richards方程拟合籽粒的灌浆过程。结果表明,孕穗期弱光处理后,籽粒终极生长量(A)有所降低,起始灌浆势(R0)、最大灌浆速率(Gmax)、平均灌浆速率(G)的变化则因品种而异;糙米率、精米率显著下降,整精米率、垩白率、直链淀粉及蛋白质含量的变化因品种而异;精米率、糙米率与籽粒A值呈显著或极显著正相关,直链淀粉含量、整精米率与籽粒的R0、Gmax、G呈显著或极显著负相关,垩白率与籽粒的G、R0、Gmax呈显著或极显著正相关。在弱光区,可以采用育种、栽培技术、化学控制等手段来改变与稻米品质密切相关的籽粒灌浆参数值,以减轻弱光胁迫对稻米品质的危害程度。  相似文献   

品种、培养基质和接种量对马铃薯脱毒基础苗生长的影响     

曹君迈  陈彦云 《干旱地区农业研究》2012,30(3):8-17

以马铃薯早熟品种大西洋、中熟品种克新1号、晚熟品种青薯168脱毒基础苗为试验材料,研究品种、培养基质和接种量对马铃薯脱毒基础苗苗鲜重、根鲜重、苗干重、根干重、叶片数、株高、茎粗、根长和根条数等性状指标的影响,培养14 d时,测定各性状指标。结果表明:三个品种的主要农艺性状均在液体培养基上表现为最佳,其平均单株鲜重、干重、株高、茎粗、节长和根条数分别为:159.4 mg、9.1 mg、7.3 cm、1.16 mm、1.4 cm、5.6条。在液体培养基上,降低了马铃薯工厂化生产成本,同时还可缩短马铃薯脱毒基础苗培养时间7~9 d。接种量对马铃薯单株根鲜重、苗干重、叶片数、株高、茎粗、根长有显著性影响(P<0.05);不同成熟期品种苗鲜重、根鲜重、根干重、叶片数、株高、茎粗、根长和根条数受品种影响显著(P<0.05);不同成熟期品种、不同接种密度处理对马铃薯单株根鲜重、苗干重、根干重、叶片数、株高、茎粗、根长影响有显著性交互作用(P<0.05);早熟品种大西洋,接种密度为0.67株/cm2时,中熟品种克新1号和晚熟品种青薯168接种密度为0.80株/cm2时,综合农艺性状表现最好。  相似文献   

Effect of early infection on pathotype frequencies in barley powdery mildew (Blumeria graminis f.sp. hordei) populations in field plots     

L. Bousset †  B. Schaeffer  C. de Vallavieille-Pope 《Plant pathology》2001,50(3):317-324

A field experiment with barley powdery mildew ( Blumeria graminis f.sp. hordei ) was designed in order to study how the time of arrival of inoculum in the field influenced pathotype frequencies in the resulting populations. Three isolates belonging to pathotypes that were absent or rare in the local aerial inoculum were used to inoculate field plots of winter barley cv. Plaisant. Two successive inoculations with different combinations of the three isolates were performed with an approximately two-generation delay, and frequencies of inoculated pathotypes were assessed four and nine generations after the first inoculation. Pathotypes of the first inoculated isolates generally persisted throughout the period of sampling; this is described as an 'early arrival' effect. During the epidemics the inoculated isolates were not replaced by isolates from the natural airborne inoculum. Pathotype frequencies depended mainly on the time of arrival of inoculum in the plot, but frequencies also depended on the isolate that had been inoculated. The most frequent isolate, GL1, belonged to the clonal lineage dominant in powdery mildew populations on winter barley in the north of France. These results confirmed that the composition of a powdery mildew population in a field is largely determined by the composition of the initial inoculum.  相似文献   

Epidemiology of Fusarium Infection and Deoxynivalenol Content in Winter Wheat in the Rhineland, Germany     

B. Birzele  A. Meier  H. Hindorf  J. Krämer  H.-W. Dehne 《European journal of plant pathology / European Foundation for Plant Pathology》2002,108(7):667-673

Details of our long-term research programme concerning the epidemiology of Fusarium spp. and mycotoxin production are summarized. Evaluation of the occurrence of Fusarium spp., mainly on winter wheat (Triticum aestivum), was carried out by investigating Fusarium infection and mycotoxin contamination. Two to 15% of grains were infested during 1995–1998 at three climatologically differing localities of the Rhineland, Germany. Disease progress was accelerated by rainfall during the flowering season. The species most frequently isolated were Fusarium avenaceum, F. poae, F. culmorum and F. graminearum. The mean deoxynivalenol (DON) content varied from 19gkg^–1 (1995) to 310gkg^–1 (1998) and was not always correlated with disease severity. Organic farming systems showed lower rates of infection with ear blight and lower mycotoxin contamination than conventional farming systems.  相似文献   

高寒地区小黑麦在断奶初期奶公犊瘤胃内动态降解的研究     

尹君亮  陈宁  宋志强  刘福元  李国庆  李周权 《中国草食动物》2006,26(4):13-15

选用3头3月龄左右装有瘤胃瘘管的荷斯坦奶公犊,按3×3完全拉丁方试验设计,喂给3种日粮,日粮组成按精粗比分别表示为:Ⅰ组70∶30、Ⅱ组60∶40、Ⅲ组50∶50,研究不同日粮组成下高寒地区小黑麦的DM、CP以及NDF在断奶初期奶公犊瘤胃内动态降解。试验结果表明:精粗比为60∶40日粮时,其CP的消失率和降解参数明显低于精粗比为70∶30和50∶50的日粮,差异显著(P<0.05);其DM和NDF的消失率和降解参数明显高于精粗比为70∶30和50∶50的日粮,差异显著(P<0.05)。  相似文献   

Heterogeneity of the aerial concentration and deposition of ascospores of <Emphasis Type="Italic">Venturia inaequalis</Emphasis> within a tree canopy during the rain     

O. Carisse  D. Rolland  B. Talbot  S. Savary 《European journal of plant pathology / European Foundation for Plant Pathology》2007,117(1):13-24

Scab is an important disease of apple and its control depends almost exclusively on frequent use of fungicides. Primary scab infection in the spring assumes several steps: ascospore maturation, liberation of ascospores that become airborne, deposition on susceptible tissues, and infection. However, the spatial heterogeneity of ascospores within the tree canopy is unknown. Aerial concentration of ascospore (ACA), ascospore concentration in rain water (ACR) and ascospore deposition (AD) were therefore measured at six heights (20–257 cm from the ground) with rotating-arm air samplers, funnels, and greased glass slides, respectively, during five rain events in 2001 and in 2002. In addition, ACR and AD were measured at eight locations within tree canopy at 196 cm height. Apple scab was assessed at the end of the primary infection period in each sampling location within the apple tree. A similar experimental design was used in 2003 to study the spatial heterogeneity of both AD and primary scab lesions. ACA and AD decreased with increasing height, while ACR increased with increasing height. Based on both variance to mean ratio and the power law relationship in both years, the ACR was heterogeneous, while AD was heterogeneous only during the peaks of ascospore release. The ACR was significantly higher at the centre of the trees and the AD was significantly higher at the centre and at the western edge of the trees. Only the cumulative AD was significantly correlated with apple scab lesions at the same location (r = 0.83). In 2003, a similar pattern of spatial heterogeneity within the tree canopy was observed for AD and primary scab lesion counts and there was a linear relationship (R ² = 0.84) between these two variables. It was concluded that ACR and AD within the tree canopy are not randomly distributed at least during peaks of ascospore release and that AD is a good estimate of primary scab lesion development. This spatial heterogeneity should be considered when estimating ascospore deposition using mathematical models or when quantifying ascosporic inoculum using spore samplers.  相似文献   

仔猪出生后的不同时间开始饲喂外源PIgG对其吸收的影响     

敖长金  于志红  侯先志  赵志恭  周薇 《内蒙古农业大学学报(自然科学版)》1998,(3)

选择２８头自然分娩、出生重１～１．５ｋｇ的大白猪（）×内蒙黑猪（♀）杂交Ｆ１代新生仔猪，于出生后的不同时间开始饲喂一定浓度的外源ＰｌｇＧ后对其吸收的影响进行了研究。结果表明，仔猪出生后在瓶哺条件下，把开始饲喂外源ＰＩｇＧ的时间推迟１８ｈ并不影响４８ｈ血清中的ＩｇＧ含量（ｐ＞０．８６）。  相似文献   

中国小麦条锈病流行体系与持续治理研究回顾与展望   总被引：1，自引：0，他引：1  

陈万权  徐世昌  吴立人 《中国农业科学》2007,40(Z1):3107-3113

  相似文献   

大青杨人工林初植密度控制技术的研究     

任军  范丽颖  林玉梅  范丽娜  杨轶囡  张维胜  李家海 《吉林林业科技》2005,34(1):11-13

通过大青杨初植密度试验,掌握了初植密度和胸径、单株材积、单位面积蓄积量等生长指标之间的关系,了解了施肥对树木生长的影响,确定了培育大青杨纸浆材的适宜初植密度是1111～1667株·hm 2。  相似文献