珲春市苹果梨主产区土壤微量元素地球化学特征研究

[目的]分析珲春市苹果梨主产区土壤微量元素的地球化学特征。[方法]在吉林省珲春市苹果梨果品基地采集32个表层土样和3个剖面土样,研究了微量元素在表层土壤中的含量及在土壤剖面中土壤地球化学特征。[结果]土壤微量元素Cr(K=0.894)和Co(0.904)平均含量与全国土壤平均值基本相当;As(0.341)、Hg(0.550)、Cu(0.659)、Ni(0.677)、Se(0.702)、Cd(0.774)和Zn(0.812)低于全国土壤平均值;Pb(1.029)的高于全国土壤平均值。在3个剖面中,As、Cr、Co、Cu、Zn和Ni呈现出底土层>心土层>表土层的趋势;Cd呈现出表土层>底土层>心土层;Hg和Pb呈现出底土层>表土层>心土层;而Se基本呈现出下部含量高于上部。[结论]该区表层土壤大部分微量元素含量较低;在3层剖面中未表现出明显的特征。     

红壤的供氮能力及化肥氮的去向

采用盆栽试验 ,研究了由第四纪红色黏土和红砂岩发育的不同侵蚀程度红壤以及施用有机或无机肥 1 0年以上培肥的红壤在不加外源氮肥条件下的自然供氮能力 ,以及施用1 5N肥源后肥料氮在土壤 -作物系统中的去向。结果表明 :红砂岩发育红壤 (红砂土 )的矿化量和供氮量显著高于第四纪红黏土 (红黏土 ) ,同一母质中轻度侵蚀红壤的矿化量和供氮量又显著高于重度侵蚀红壤。培肥后红壤的矿化量和供氮量显著提高 ,其中有机培肥红壤高于无机培肥红壤。侵蚀红壤的氮肥利用率低 ,土壤残留氮率较高 ,氮肥损失率不大 ,其中红砂土的氮肥残留率明显低于红黏土 ,而氮肥损失率却显著高于红黏土。培肥后红壤的氮肥利用率明显增加 ,其中有机培肥红壤的氮肥利用率和残留率显著高于无机培肥的红壤 ,而氮肥损失率却明显低于无机培肥红壤。     

两优2186制种中亲本的特征特性观察

对两优2186亲本（母本SE21S,父本明恢86）在福建省三明市沙县制种过程中的主要特征特性进行了研究和调查,结果表明：母本SE21S具有株型好、生育期长、柱头外露率高、抗性好及分蘖能力强等特性;父本明恢86具有分蘖能力强、生育期长及叶片数多等特性。通过对两优2186亲本的特征特性进行观察和研究,并就两优2186在该县高产制种管理上提出了若干建议。     

花期喷盐水结合蜜蜂授粉克服大白菜自交不亲和性试验

大白菜花期喷ＮａＣｌ溶液，结合蜜蜂授粉克服自交不亲和性的试验结果表明，喷３％ＮａＣｌ溶液效果最佳；于上午９：３０喷结籽最多；每天早晨喷３％ＮａＣｌ后在不同时间进行人工授粉均可结籽；ＮａＣｌ处理株的花粉授粉效果好于未处理株，用于授粉的蜜蜂在使用前需隔离４天，以使身上的花粉失活。ＮａＣｌ处理后的柱头乳突细胞胼胝质含量的变化与亲和性变化有相同趋势。     

内肽酶与端肽酶水解扇贝边蛋白质工艺的研究

以扇贝加工废弃物——扇贝边为原料，研究了几种内肽酶、混合内肽酶、内肽酶与端肽酶分段酶解的水解工艺。其中，采用混合内肽酶(胰蛋白酶：枯草杆菌蛋白酶=3：1，酶活力比)和F1avourzyme分段水解扇贝边蛋白质，水解效果最佳。正交试验结果表明，Flavourzyme二阶段酶水解的最适工艺条件为酶添加量250U／g(原料)、时间5．5h、温度55℃、pH6．5。蛋白质水解度达68．2％。所得水解液中游离氨基酸含量为78．40g／L，其中必需氨基酸总量为31.57g／L。     

不同营养饲量对苏禽96父母代母本生长和生产性能的影响

将饲养到9周龄的苏禽96父母代母本母鸡900只,随机分为6组,每组150只。组间体重无显著性差异。10～22周龄饲喂5个水平的日粮,2、3、4、5、6组以每天每只鸡比第1组饲喂的代谢能（J）、粗蛋白质（g)依次提高21、0.32;42,0.64;63,0.96;84,1.28。3、4组为重复组。22周龄末称重,组间差异不显著。从23周龄到48周龄,饲喂同一种日粮,第3组每天每只鸡比其它组少喂5g,其它各组鸡饲喂量相同,结果,不同饲喂水平对蛋重、成活率几乎无影响。人舍母鸡产蛋量以第5组最高,为114.16个;第1组最低;为100.69个。育成期饲喂水平相同,产蛋期饲喂水平不同的3组和4组产蛋量分别为102.53个和104.85个,差异不显著。结果表明,育成期的饲养管理对产蛋量有很大影响。     

Seasonal differences in effect of broodstock diet on spawning success in the great scallop

Great scallop (Pecten maximus L.) broodstock collected at two different seasons, spring (May) and winter (December), were given four different diets during conditioning. The spring group was spawned in late June, and the winter group in February.The highest number of veligers in the summer spawning (30 millions per 10broodstock), was produced using a diet consisting of 80% Tahitian Isochrysis galbana. In the winter spawning, broodstock given a dietconsisting of 80% diatoms (Skeletonema costatum/Chaetocerosgracilis) produced the highest number of veligers (29 millions per 10broodstock). Fecundity and the number of egg-releasing individuals were higher in the early summer spawning (June) than in the winter spawning (February), however, the total number of three days old veligers produced was nearly the same in the two seasons.     

Reproductive cycle of the south American scallop Amusium laurenti (Gmelin, 1791) (Bivalvia, Pectinidae)

Amusium laurenti is a functional hermaphroditewith well differentiated male and female gonadalareas. The gonadal index varies throughout the yearwith maximum values occurring in January, March andJuly, and minimum ones in August and September. Partial spawning (with respect to the individual andthe population) occurred from January to February andMarch to May. The major spawning event coincided withthe end of the period during which bottom watertemperature increased to temperatures above 26°C(July–August). Subsequently temperature decreased to22°C, with a period of gonadal restoration andincreasing gonadal index. Histological analysis ofthe gonads correlated with the gonadal index.     

Mortality of scallop spat in cultivation, infested with tube dwellingbristle worms, Polydora sp.

Between 1995 and 1997, a traditional Norwegian oyster poll with an attachednursery was used for the production of scallop (Pecten maximus) spat.During summer 1997, four batches of 2 mm scallop spat were placed in thenursery. In June, hydroids (Obelia) caused problems with fouling andaccumulation of sediment in the nursery. Thereafter, the scallop spat wereheavily infested with tube dwelling polychaets (Polydora sp.). Thepolychaets were both introduced with poll water and reproduced inside thenursery. Infested spat suffered high mortalities. Although the spat could have been affected by the hydroids, as well as shortage of food, Polydorainfestations were considered the main cause of the mortalities. Dead andinfested spat were continuously sorted out and discarded, but the infestationproblems persisted. As a result, the scallop spat did not represent anycommercial value for the company, and in September, the nursery wasemptied. In total, approximately one million spat – representing onethird of Norway's intensive scallop spat production in 1997, was lost.     

我国海湾扇贝养殖现状、问题与发展对策

据统计,到１９９８年我国海湾扇贝养殖面积发展到近７０００ｈｍ＾２,养殖产量约３０万ｔ。特别是自１９９７年栉孔扇贝养殖出现大面积死亡以来,海湾扇贝养殖面积不断扩大。但在１９９９年贝苗中间暂养阶段发生了大量死亡,造成养殖苗种严重不足,使养殖面积减少约２／３,经济损失惨重。作者就海湾扇贝养殖中存在的问题进行了分析,并对今后的发展提出了一些设想。