云南“帕拉英达”芒果叶片营养规律研究

通过对云南保山地区“帕拉英达”芒果成熟功能叶片中N、P、K、Ca、Mg、S等 6种营养元素含量进行跟踪分析,结果表明：叶片养分年平均含量大小为： Ca＞N＞K＞P＞Mg＞S,其全年平均含量（g/kg）分别为：25.16、15.20、4.56、1.39、1.35、1.34;不同生育期叶片养分含量变化规律有所差异,根据叶片养分含量的变化规律,可把“帕拉英达”芒果生长周期分为4个阶段：营养生长期(8－次年1月)、生殖生长期(1－3月)、果实膨大期(4－5月)、果实成熟期(6－7月)。     

海南台农和金煌芒叶片养分周年动态变化分析

对海南主栽芒果品种台农和金煌芒的叶片养分的变化动态进行了分析。结果表明,相同栽培模式下,芒果叶片养分含量在不同品种、不同生长发育阶段和不同物候期之间存在显著的差异,但总体规律为：Ca＞N＞K＞Mg＞P＞Mn＞Fe＞Cu＞Zn。营养生长期间,不同月份芒果叶片中N、P、K、Mg含量基本保持在同一水平上;生殖生长期间,养分从叶片转移至花芽中,叶片养分明显下降。对于大量元素N、P、K、Mg而言,8月份至12月份叶片养分波动较小,因此10月份芒果的叶片可以作为叶片营养诊断的采样时间。     

台农芒果干物质及养分积累研究

通过枝解法采集高产和低产树果树不同生育期不同器官干物质并进行分析,研究海南“台农一号”芒果年周期干物质积累量和养分积累量,为平衡施肥提供科学依据。结果表明：（1）营养生长期、花期、果期三个阶段干物质积累量之比约为3：2：5,不同器官干物质积累量大小顺序均为：果＞叶＞枝＞落花≈落枝≈落果。（2）生产1000kg鲜果,所需N、P、K、Ca、Mg纯养分量分别为：2.86~2.95kg,0.43~0.49 kg,3.21~3.60 kg,2.30~2.77 kg,0.27~0.42 kg。(3) 叶片N、P养分积累量与果实养分积累量有较强相关性,且果实N、P、K养分之间两两极显著相关,存在协同作用。     

椪柑果实品质因树龄的变化及其与叶片-土壤养分含量的关系

研究选择树龄依次为5、8、13和18年椪柑（Citrus reticulate Blanco ?Poncirus trifoliate）为对象,测定、分析椪柑果实品质及叶片养分含量、对应的土壤养分性状,旨在揭示椪柑果实品质随树龄的变化及其与叶片-土壤养分关系。结果表明,5至8年树龄椪柑果实单果重大且果形偏扁;13年树龄椪柑果实单果重小且果形偏圆;18年树龄椪柑果实单果重大且果形偏扁,果实可溶性固形物含量（10.72%）低,可滴定酸含量（1.02%）高,固酸比（10.70）低。随着树龄延长,叶片N和P含量先降低后升高,Zn含量先升高后降低,K、Mg和Mn含量上升,Ca和B含量下降。椪柑果实可溶性固形物与叶片Ca/K、Ca/Mg、Ca/Mn、Ca/(K Mg)、Ca/(Mn＋Fe)、Zn/(Mn＋Fe)呈显著正相关;可滴定酸含量与叶片Ca/K、Ca/Mn、Ca/(K Mg)呈显著负相关。结果显示,较长树龄椪柑果实可溶性固形物含量低、可滴定酸含量高与叶片低Ca、Zn含量和高K、Mg、Mn含量有关。     

桂热芒82号叶片矿质营养诊断采样时间和采样部位的研究

本研究通过综合比较桂热芒82号叶片氮、磷、钾、钙、镁、硫等6中矿质营养元素在不同月份的变异系数及离年均差大小,得出：花芽分化前期或5月叶龄（12月份）叶片中氮、磷、钾、钙、镁、硫等6中矿质元素变异小和离年均差小,桂热芒82号两蓬叶片矿质元素含量稳定且能代表全年树体营养状况,故12月份适宜作为营养诊断采样时间;通过对比桂热芒82号两蓬叶片中矿质元素在不同年份中12月份间差异比较,得出第一蓬叶片在不同年份间差异小,故第一蓬叶片适宜作为营养诊断采样部位。综合得出,桂热芒82号叶片营养诊断在12月份采集第一蓬叶片较为适宜。     

七叶树叶片营养与立地土壤状况的相关性分析

为了探讨行道树七叶树的叶片营养和立地土壤状况的相关性,以便七叶树能良好生长,充分发挥其生态功能,采用野外调查与室内试验分析相结合的方法,对兰州市主城区(城关、七里河、安宁和西固)的七叶树叶片及立地土壤分季节(夏季和秋季)进行分析.结果 表明:(1)七叶树叶片含水量、全N、全K和全Cu含量夏季高于秋季;叶片叶绿素和全P含量表现为夏季较高;叶片Ca、Mg、Fe含量秋季高于夏季;(2)整体土壤状况表现为pH值偏高,有机质、水解N、交换性Mg、有效Cu和有效Fe的含量较低;(3)夏季叶片相对含水量与土壤交换性Ca和交换性Mg含量显著负相关(P＜0.05);叶绿素含量与土壤有效Cu和有效Fe含量显著正相关(P＜0.05);全N、P、K均与土壤交换性Ca含量极显著正相关(P＜0.01),与土壤交换性Mg显著正相关(P＜0.05);叶片中Cu含量与土壤速效N、P均呈显著负相关(P＜0.05);秋季叶片中交换性Ca含量与土壤速效N含量显著正相关(P＜0.05);其余的叶片营养元素含量和土壤养分含量之间的相关性均不显著.在今后的养护管理中应根据叶片和土壤的实际营养状况,结合不同生长期对养分的需求合理施肥.     

N素营养对NaCl胁迫下盐地碱蓬幼苗生长及渗透调节物质变化的影响

通过NaCl和N对盐地碱蓬幼苗生长及渗透调节物质变化的影响研究,结果表明,NaCl和N素对植物的生长的影响是明显的(P<0.05),低NaCl胁迫下N含量的增加对盐地碱蓬幼苗生长的影响不明显,而高NaCl处理下增加营养液中N的含量能明显地缓解盐胁迫,促进盐地碱蓬幼苗的生长.叶片脯氨酸含量随着NaCl浓度和养分N含量的增加而增加,而可溶性糖含量减少. NaCl浓度的增加使得植株总离子含量、Na 含量增加,K 、Ca2 、Mg2 含量减少.随N养分含量的增加,叶中Na 和K 含量增加, Mg2 含量基本上呈减少的趋势.叶片中的Ca2 含量和植株根茎部各离子含量随养分N含量增加的变化规律不明显.     

纽荷尔和清家脐橙果实大量元素含量与累积变化

以30年生枳砧清家脐橙和纽荷尔脐橙为材料,分析果实生长发育过程中N、P、K、Ca、Mg、和S 6种大量营养元素含量和累积量变化。结果表明,果实生长发育过程中,纽荷尔和清家果实中N、P、Mg和S含量4月最高,Ca在10月最高,纽荷尔和清家K含量分别在9月和7月最高;纽荷尔果实的N、P、K、Mg和S主要累积时期为7～9月,Ca主要累积时期为9～10月;清家果实的N、P、K、Mg和S主要累积时期为6～8月,Ca主要累积时期为8～10月。清家脐橙果实中大量营养元素的主要累积时期比纽荷尔脐橙早1个月左右。     

红三叶N、P、K、Ca、Mg元素含量与动态研究

本文研究了红三叶（Trifoliumpratense）各器官在不同生育期N、P、K、Ca、Mg等元素的含量，目的在于揭示其各器官对N、P、K、Ca、Mg的积累能力、对不同元素的选择性吸收以及N、P、K、Ca、Mg在各器官的季节动态。结果表明：红三叶不同器官对各元素的积累能力不同，N：叶＞花＞根＞茎；P：花＞叶＞根＞茎；K和Ca：叶＞花＞茎＞根；Mg：根＞叶＞茎＞花。不同器官对元素选择性吸收系列不同，根为N＞K＞Ca＞Mg＞P；茎：N＞Ca＞K＞Mg＞P；叶：N＞Ca＞K＞P＞Mg；花：N＞Ca＞K＞P＞Mg；红三叶是一种典型的N－Ca型植物。此外，K、P、K、Ca、Mg在根、茎、叶、花中的动态变化有6种基本类型，Ⅰ－渐增型（／）、Ⅱ－递减型（＼）、Ⅲ－U型、Ⅳ－∩型、Ⅴ－增波型（～）、Ⅳ－降波型（～）。     

紫穗槐植株的养分含量及分布特征

为了探明紫穗槐植株的营养结构特征,测定了生长季(6,7,8,9月)紫穗槐叶和不同径级根、茎的10种养分(有机碳、N、P、K、Ca、Mg、Fe、Mn、Cu、Zn)含量。结果表明,1)根和茎的N、P、K含量与径级呈典型逆相关关系,即随着径级的增大养分含量减少,含量最高的部位集中于叶及小径级的根、茎。2) 各级根、茎的Ca、Mg、Fe、Mn、Cu、Zn含量没有固定的分布特征。3)微量元素间的相关性比其与大量元素的相关性差,茎中所含相关元素对最多,其次是叶,根最少;从元素方面看,N、P、K与较多的元素间存在相关性,与C、Zn、Ca相关的元素较少。4)生长季紫穗槐叶的C、N、Ca、Mn、Cu含量高于根和茎,叶中大量元素的含量顺序为C＞N＞K＞Ca＞Mg＞P,微量元素为Fe＞Mn＞Zn＞Cu。     

Scrapie in goats in Cyprus

Ovine scrapie was first recorded in Cyprus in 1985. Subsequently four dairy goats kept in two mixed flocks with affected sheep developed characteristic clinical signs similar to those seen in sheep. Fifteen goats from the two flocks were examined histologically and neurological lesions consistent with a diagnosis of scrapie were found in the four animals and in three others which had subsequently developed early neurological signs. These lesions were similar to those of naturally-affected sheep although neuronal degeneration and vacuolation were more severe in some cases.     

Heartworm in dogs in Canada in 1984

In late December 1984, 1853 institutional veterinarians and small and mixed animal clinics across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1984 and 35% of them responded. Veterinarians reported that 97,794 dogs were blood-tested to check for microfilariae and 1417 dogs (1.45% of those tested) were found with heartworm. Another 34 dogs were amicrofilaremic, but were diagnosed as having heartworm disease, to give the total number diagnosed in 1984 as 1451 (1.48%). Heartworm was reported from all provinces except Prince Edward Island and Newfoundland but most (1310) of the cases were in Ontario. In Quebec, 126 cases were reported mostly from west of Montreal.

Heartworm was found most frequently in companion dogs over three years of age maintained mainly outdoors in rural areas. About 27% of the cases were observed with clinical signs of heartworm disease and 72% had a history of not having left Canada. Southwestern Ontario continued to be the primary focus of the infection.

     

Heartworm in dogs in Canada in 1983

In late December 1983, 2 800 veterinarians across Canada were sent a questionnaire in order to assess the status of heartworm disease in Canada in 1983 and 26% of them responded. Veterinarians reported that 59 504 dogs were blood-tested to check for microfilariae and 771 dogs (1.30% of those tested) were found with Dirofilaria immitis. Heartworm disease was diagnosed in all provinces except New Brunswick and Newfoundland but most (733) of the cases were in Ontario.

Heartworm disease was found most frequently in companion dogs over three years of age maintained mainly outdoors in rural areas. About 31% of the cases were observed with clinical signs of heartworm disease and 64% had a history of not having left Canada. Southwestern Ontario continues to be the focus of the infection and most of the dogs there had not left the province previously.

     

Heartworm in dogs in Canada in 1985

In late December 1985, 1485 institutional veterinarians and small and mixed animal clinics across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1985 and 44% of them responded. Veterinarians reported that 137,300 dogs were blood-tested to check for microfilariae and 1210 dogs were found with heartworm. Another 36 dogs were amicrofilaremic but diagnosed with heartworm disease to give the total number diagnosed in 1985 as 1247 (0.91%).

Heartworm was reported from all provinces except Prince Edward Island, Newfoundland and Saskatchewan but most (1126) of the cases were in Ontario. Southwestern Ontario continued to be the primary focus of the infection in Canada. From Quebec, 91 cases were reported mostly from and around Montreal. From Manitoba, 19 cases were reported from Winnipeg and surrounding areas. Heartworm was found most frequently in companion dogs over three years of age maintained mainly outdoors in rural areas. About 28% of the cases were observed with clinical signs of heartworm disease and 78% had a history of not having left Canada.

     

Heartworm in dogs in Canada in 1988

In late November 1988, 1581 small and mixed animal clinics and institutional veterinarians across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1988, and 46% of them responded. Veterinarians reported that 181,577 dogs were blood-tested for heartworm disease and 367 dogs were found with D. immitis microfilariae. Another 60 dogs were amicrofilaremic but diagnosed with heartworm disease to give the total number of cases diagnosed in 1988 as 441 (0.24%).     

Heartworm in dogs in Canada in 1991

In late November 1991, 1883 clinics in Canada were sent a questionnaire to assess the status of Dirofilaria immitis in dogs in 1991 and there was a 60.0% response. There were 344,031 dogs tested for heart-worm (HW), 627 were found infected and the prevalence of HW infection was 0.18%. There were 417 dogs with HW in Ontario, 116 in Manitoba, 38 in Quebec, 53 in British Columbia, three in Alberta, and one in Nova Scotia. In British Columbia, all of the infected dogs but one were from the Okanagan valley which, as from 1991, is a new focus of infection in Canada. Most dogs with HW had not been on preventive medication in 1990, and the prevalence among dogs tested and unprotected was 0.59%. That prevalence was considerably higher in endemic areas. Companion dogs, over three years of age and maintained primarily outdoors in rural areas, were most frequently infected. One cat was diagnosed with D. immitis and 33 dogs had Dipetalonema reconditium.     

Heartworm in dogs in Canada in 1989

In late November 1989, 1732 clinics and institutional veterinarians were sent a questionnaire to assess the status of Dirofilaria immitis, and 51.7% responded. Of 247,716 dogs tested, 394 had D. immitis microfilariae and 51 were amicrofilaremic for a total of 445 cases and heartworm prevalence of 0.17%. Most (408) of these dogs had no preventive medication and the prevalence among dogs tested and unprotected was 1.01%. That prevalence was considerably higher in endemic areas. Thirty-seven dogs with heartworm had preventive medication. Heartworm was most frequent in companion dogs over three years of age maintained outdoors in rural areas. About 75% of the cases had never left Canada, 26% had clinical signs and 125 were not treated.

Heartworm was reported from British Columbia, Manitoba, Ontario, Quebec, Nova Scotia and Newfoundland, but 383 cases were in Ontario. South-western Ontario was the primary focus of infection. There were 33 cases in Quebec and 24 in Manitoba, mainly found in and around Metropolitan Montreal and Winnipeg respectively.