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31.
[目的]从根本上改变青海省梨树栽培的落后局面,解决果实品质和产量下降的问题。[方法]从辽宁、山西引进梨矮化砧木19种[从中国农业科学院辽宁兴城果树研究所引进s2(中矮1号)、PDR54(中矮2号)、和s5接穗,从山西省果树研究所引进K系矮化砧木接穗16种,分别为K1、K2、K3、K4、K7、K8、K9、K11、K12、K13、K14、K15、K16、K21、K28、K311,进行嫁接试验,筛选优良软儿梨(Pyrus ussu-riens/sMaxim.)矮化密植砧木。[结果]19种矮化砧木嫁接成活率较高,生长表现良好,能适应当地气候特点,安全越冬的品种为中矮1号,其嫁接软儿梨后,矮化程度为72.3%,保持了其作为半矮化砧木的矮化潜力。[结果]该研究可填补青海省梨树矮化密植栽培的空白,开创了青海省果树栽培的新局面。 相似文献
32.
四倍体小麦矮杆地方品种的C带分析 总被引:4,自引:0,他引:4
矮杆番麦是四倍体小麦地方品种罕见的矮杆种质,采用改主的C带技术对基尖细胞染色体进行了分析,矮杆番麦体细胞具14对染色体,染色体组型AABB。非同源染色体之间,带的数目,大小,强弱及分布情况各异,根据其特殊的带型,容易将筹杆番麦的单条染色体及分开,据此认为C带可作为矮杆番麦染色体的细胞学标记,矮杆番麦的带型与原始类型的野生二粒小麦相似,表明其基因未发生过大的染色体重排,因此,矮杆番麦的矮杆性状不是由 相似文献
33.
矮小型褐壳蛋鸡产蛋时间和间隔的统计分析 总被引:4,自引:0,他引:4
本文对880只纯系矮小型褐壳蛋鸡的产蛋时间进行了连续5天的观察,分析结果表明,矮小型褐壳蛋鸡的产蛋时间集中在上午12时以前,并以9:00~10:00期间产蛋最为密集,占全天产蛋的19.5%。连产内第一枚蛋产出时间集中在上午(89:33%),以7:00~9:00间产蛋最多(49.71%);而最后一枚蛋产出时间集中在下午(71.20%),以2:00~4:00间产蛋最多(36.58%)。矮小型褐壳蛋鸡连产内产蛋间隔范围为22.35~31.15小时,每枚蛋平均间隔高峰在24小时(36.0%),群体平均产蛋间隔为25.08小时。相邻连产间间隔时间的变异范围很大,最短为38.0小时,最长达100.45小时。 相似文献
34.
We observed that the growth of three Amaranthaceae species was promoted by sodium (Na), in the order dwarf glasswort (Salicornia bigelovii Torr.) >> Swiss chard (Beta Burgaris L. spp. cicla cv. Seiyou Shirokuki) > table beet (Beta vulgaris L. spp. vulgaris cv. Detroit Dark Red). In the present study, these Na-loving plants were grown in solutions containing 4 mol m?3 nitrate nitrogen (NO3-N) and 100 mol m?3 sodium chloride (NaCl) and potassium chloride (KCl) under six Na to potassium (K) ratios, 0:100, 20:80, 40:60, 60:40, 80:20 and 100:0, to elucidate the function of Na and K on specific characteristics of Na-loving plants. The growth of dwarf glasswort increased with increasing Na concentration of the shoot, and the shoot dry weight of plants grown in 100:0 Na:K was 214% that of plants grown at 0:100. In Swiss chard and table beet, growth was unchanged by the external ratio of Na to K. The water content was not changed in Swiss chard or table beet by the external Na to K ratio. These observations indicate that both Na and K have a function in osmotic regulation. However, dwarf glasswort could not maintain succulence at 0:100; therefore, Na has a specific function in dwarf glasswort for osmotic regulation to maintain a favorable water status, and the contribution of K to osmotic regulation is low. NO3-N uptake was promoted by Na uptake in dwarf glasswort and Swiss chard. NO3-N uptake and transport to shoots was optimal at 100:0 in dwarf glasswort and at 80:20 in Swiss chard. These functions are very important for the Na-loving mechanism, and the contribution of K was lower in dwarf glasswort than in Swiss chard. 相似文献
35.
Seiki Takatsuki 《Biological conservation》2009,142(9):1922-1929
The Japanese sika deer Cervus nippon has expanded its range by nearly 70% during the last two decades. Browsing by sika deer affects vegetation in both agricultural and forested habitats. Effects of sika deer on vegetation are conspicuous on deer-inhabited islands: forest structure and composition are altered by deer grazing and browsing, and consequently regeneration is prevented. By felling of old trees, forest gaps are formed, but since sapling recruitment is prevented, shade intolerant plants invade. Unpalatable forbs like ragwort Senecio cannabifolius and ferns like bracken Pteridium aquilinum (Dennstaedtiaceae) become dominants in open habitats. At the places of highest deer density, the Zoysia japonica community, a low growing grass mat, develops. Sika deer function as a seed dispersal agent of this grass. Indirect effects of sika deer are not well studied, but some studies have shown reduction of understory bamboo cover, which in turn improves the survival of tree seedlings and declines of wood mice Apodemus spp. Japanese forests in lower mountainous areas were widely logged during the 1940s and 1950s. These areas were not well planted during the war and until 1950, but thereafter intensively planted to alter to conifer plantation as a nationwide campaign. For several decades after the war, rodents and hares grazed planted trees. According to growth of the planted trees to form canopy, which is unfavorable for rodents and hares, their damage declined. After the 1960s, old-growth forests in high mountainous areas were logged, and conifers were planted. Animals causing forestry damage were replaced by sika deer during the 1980s. Sika deer eat a wide variety of foods, and are gregarious, which causes heavy impacts on vegetation. Effects of sika deer are expanding to natural forests, alpine vegetation, and marshes. To reduce damages on forestry and natural vegetation, as many as 100,000 sika deer are culled every year. However, the hunter population is rapidly declining, and it is expected population control by culling will be insufficient. Although sika deer are an important component of Japanese forests, current population densities exceed the capacity of many ecosystems to tolerate herbivory. 相似文献
36.
37.
利用EMS诱变籼型水稻恢复系缙恢10号,获得一个稳定遗传的矮化脆性突变体dbc1,苗期即表现矮化、叶片变脆,一直保持到成熟。与原始亲本相比,突变体的各节间均显著缩短,株高仅58.93 cm,略有包穗,属于dn型矮化变异,对赤霉素的敏感性显著下降,有效穗、千粒重和结实率无明显变化,穗长、穗粒数和实粒数则极显著下降。进一步分析发现,dbc1的茎秆和叶片的载荷强度极显著下降,纤维素含量无变化,木质素含量则略有下降,差异达显著水平。遗传分析表明该性状受1对隐性核基因调控,利用886株西农1A/dbc1的F2变异单株,最终把DBC1基因定位在第2染色体SSR标记RM13943和RM13952之间,物理距离仅197 kb,含有52个注释基因。这为下一步调控基因的克隆和dbc1材料的育种应用奠定了基础。 相似文献
38.
糯小麦矮源新种质 11-805矮秆性状遗传研究 总被引:2,自引:1,他引:1
11-805是绵阳市农科院新创制的糯小麦矮源种质,为了深入了解新创种质糯小麦矮源11-805的矮秆性状遗传规律,试验对11-805的矮秆遗传特性进行了较为系统的研究。用11-805与高秆亲本‘绵麦37’、‘绵麦43’和‘绵麦1618’杂交,从正反杂种F1代株高表现可知,其F1代株高介于高亲值与中亲值之间,且D为负值,说明11-805的矮秆特性主要受隐性矮秆基因控制;3个群体F2代株高分离出矮秆、半矮秆、高秆3个类型,其比例均为1:2:1,同时有超亲分离存在。结果表明,11-805的矮秆性状是由1对隐性基因控制,并受一些微效基因的影响。正反交F1代平均株高降幅为16.07%和15.67%,可以表明矮秆糯小麦11-805具有明显降低株高的特性。 相似文献
39.
40.
糖基转移酶基因sm-Ngt1对水稻株高的影响 总被引:2,自引:0,他引:2
[目的]研究烟草中受甲基茉莉酸和水杨酸双重诱导的糖基转移酶基因sm-Ngt1过表达对水稻生长的影响。[方法]构建sm-Ngt1的植物表达载体,采用农杆菌浸染法转化籼稻粤泰B,对获得的阳性转基因植株进行高度检测。[结果]共获得117株阳性转sm-Ngt1植株。在成功转入sm-Ngt1基因后,水稻植株出现了不同程度的矮化,其中37%的转基因植株高度为71.4±9.8cm,27%的转基因植株高度为65.1±4.6cm,而未转基因的对照YTB的平均高度为130.0±4.3cm。[结论]为进一步研究sm-Ngt1的功能奠定了基础。 相似文献