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1.
Trunk disease is a major problem on grapevine in Zanjan province, causing serious decline, despite which its aetiology remains unknown. The purpose of this study was to investigate factors involved in grapevine decline in vineyards of Zanjan province. Samples were collected from twigs and branches of grapevines in the region between October and November 2018. Fungal isolates were identified based on morphological characteristics and ITS-rDNA sequence data for selected isolates. The frequency and diversity of the fungal community recovered from grapevines in Darreh Sejin in Zanjan province were higher than in other regions. A total of 112 fungal isolates comprising 22 species were recovered. Phaeoacremonium minimum, Microsphaeropsis olivacea and Kalmusia variispora were identified as the dominant species in the region examined and could be considered the main trunk pathogens of grapevines in Zanjan region. In inoculation tests, M. olivacea was proved to be pathogenic on grapevine for the first time in this study.  相似文献   
2.
贾隽 《青海农林科技》2014,(1):13-14,73
青海云杉小卷蛾为云杉小卷蛾属新种,在青海西宁地区主要危害青海云杉,在我国青海西宁发生较为严重。由于小卷蛾虫体过小不易观察,危害隐蔽,监测、防治难度较大,蛹羽化期集中,一旦成虫出现,很快进入盛期,预报有效防治期很难把握,防治效果较差。经过三年观测发现青海云杉小卷蛾的生活史与青海云杉物候期有着密切的依从关系,以青海云杉物候观测为参照,可掌握青海云杉小卷蛾虫害的发生规律和最佳防治时期。  相似文献   
3.
Morphological changes in the embryos, egg size and development, incubation period and morphological structures of newly hatched zoea of three mud crab Scylla species were determined. The three species exhibited similar embryonic development composed of 10 stages. The mean egg diameter of Scylla serrata was significantly larger (P<0.05) at the prehatch stage. The mean egg diameters of Scylla tranquebarica and Scylla olivacea were similar (P>0.05). The incubation period was the longest in S. serrata and the shortest in S. olivacea. There was a positive relationship between egg size and larval size, as S. serrata exhibited the largest egg size and first zoea. However, no correlation was detected between egg size at prehatch and lengths of the morphological structures of the newly hatched zoea. The three species exhibited similar lengths of cephalic structures, but S. olivacea had significantly shorter (P<0.05) abdominal structures. The duration of spawning from ablation was the shortest in S. tranquebarica and the longest in S. olivacea. The study is relevant to aquaculture and fisheries management of Scylla species.  相似文献   
4.
The proximate composition and antioxidant properties of the muscle tissues of Scylla olivacea are reported herein. The carbohydrate content was in the range of 1.52% to 3.07%, while protein varied from 13.30% to 17.28%. Meanwhile, the fat content for S. olivacea was found to be ranging from 0.20% to 0.57%. The moisture content in S. olivacea was 60.00%. Generally, no significant differences were observed in both male and female tissues of S. olivacea regarding its total phenolic content, 2,2-Diphenyl-1-(2,4,6-trinitrophenyl) hydrazyl (DPPH) scavenging, and superoxide dismutase activities. However, significant differences were observed for the total flavonoid content and activity of catalase. The present results revealed the nutritional information and enzymatic and nonenzymatic antioxidant status of the tissues of S. olivacea.  相似文献   
5.
盐度对紫彩血蛤胚胎及幼虫发育的影响   总被引:1,自引:0,他引:1  
就盐度对紫彩血蛤胚胎及幼虫发育的影响进行了研究,结果:紫彩血蛤胚胎发育的有效盐度范围为16.07~37.04,最适盐度范围为23.95~31.03。盐度为23.95,胚胎发育速度最快,孵化率最高,达98%,幼虫发育的适宜盐度范围为16.07~37.04,其中盐度为28.03,幼虫存活率和变态率最高,分别为78.8%和88.6%,盐度12.02~40.95对幼虫均无明显致畸影响。  相似文献   
6.
紫彩血蛤的生长   总被引:1,自引:0,他引:1  
孙虎山 《海洋渔业》1998,20(4):163-166
本文以1994~1996年烟台牟平港西沙滩自然生长的紫彩血蛤为材料,研究了其生长特点。鲜贝重与壳长呈幂函数关系,W=3.955×10~(-5)L~(3.275);壳长与壳高呈直线关系,L=1.980+1.274H;3~6月贝壳生长最快,7~9月生长最慢;3、4两月肉质部增重最大;其生长随年龄的增加呈递减趋势。  相似文献   
7.
紫彩血蛤低温保活技术研究   总被引:6,自引:1,他引:6  
[目的]研究紫彩血蛤在低温条件下的保活效果。[方法]以紫彩血蛤为原料,测定了它的冻结曲线并对其在生态冰温区域内和冰块堆积条件下以及不同冷藏温度和湿度下的保活效果进行了比较。[结果]紫彩血蛤的生态冰温区大致在0~-2℃。随着温度的升高,紫彩血蛤的存活率逐渐降低,存活率最高的组为冰温保藏组(-1.5~-0.5℃),在保活10 d后其存活率依然达99%。淡水冰堆积组和4~6℃组保活效果较好,在保活7 d后,两者的存活率均达99%,而且总体表现接近。湿度对紫彩血蛤保活效果有一定的影响,呈正相关性,相对湿度越高越有利于蛤体的存活。[结论]该研究为紫彩血蛤的实际生产应用提供了理论依据。  相似文献   
8.
Takeshi  TOMIYAMA  Koichi  SASAKI  Michio  OMORI 《Fisheries Science》2004,70(4):531-536
ABSTRACT:   The purpose of the present paper was to examine the size relationship between the juvenile stone flounder Platichthys bicoloratus and the bivalve Nuttallia olivacea , the siphon of which is important prey for the juvenile flounder. Juvenile stone flounder feed mainly on tips of the inhalant siphon of the bivalve. The maximum width of siphon tips in the stomach contents of age-0 fish could not reach that of age-1 fish, although the siphons in age-0 fish became larger as they grew. This size discrepancy indicated a limitation in the size of bivalves available to juveniles. The proportion of total cropping frequency for the siphon of the bivalve by juveniles was estimated according to the bivalve size class. Most bivalves that had cropped siphon tips ranged from 5 to 30 mm in shell length. The total cropping frequency per bivalve was particularly intense on bivalves of 10–25 mm shell length in spite of their small proportion of 24.9% of the total. This frequency intensity indicated that the size of bivalves with cropped siphons by juvenile stone flounder might depend on the ability of juveniles rather than the size composition of the bivalves.  相似文献   
9.
10.
黄河三角洲河蚬软体部营养成分的分析及评价   总被引:1,自引:0,他引:1  
对黄河三角洲流域分布的河蚬软体部营养成分进行了分析,综合评定其营养价值.结果表明,河蚬软体部干样中,粗蛋白、粗脂肪、灰分含量分别为53.90%、8.90%和1.33%;共测到了17种氨基酸,必需氨基酸占氨基酸总量的37.44%,大部分必需氨基酸分(AAS)在40分以上,含硫氨基酸(半胱氨酸+蛋氨酸)为第一限制性氨基酸, 色氨酸得分最高为124.00分;共分析了10种主要脂肪酸,其中EPA、DHA含量分别占7.62%和8.61%.河蚬富含钙、钠、镁、钾、铁等11种无机元素,维生素A、B含量也较丰富.对紫彩血蛤的脂肪酸组成及含量进行了检测, 其中EPA、DHA含量分别占15.23%和6.45%.  相似文献   
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