小麦品种群体的细胞学研究

对９个小麦品种群体进行了细胞学观察。结果表明,４．５３％的细胞含有至少一对不配对的染色体,２．３１％的细胞里,染色体偏离正常的数目。显然,这种自然的不规则性可能导致非整倍体后代的产生。３．５７％的细胞发生了易位,群体的２．２２％为单体植株。     

半干旱黄土丘陵区沙棘优良品种引种选育试验研究

1985-1998年先后在黄土高原半干旱区的陕西吴旗,安塞县进行了沙棘优良品种引种选育试验研究。通过引种国内不同地理种源20余种优良沙棘类型。引进俄罗斯优良沙棘品种,采用家系选择法进行试验研究,初步筛选出生态经济型5种沙棘类型,经济型2种类型。前者生长迅速,树冠好,根系发达,郁闭快,水土保持效益好,且果实较大（果径0.8-0.9cm,百果重20-31g),单株产果量为2-3.5kg,Vc和含油量较高,其生态,经济性状较当地野生沙棘为好。此种类型沙棘适于在黄土丘陵大面积荒沟,荒坡种植,通过引种俄罗斯大果,无刺沙棘为好。此种类型沙棘适于在黄土丘陵大面积荒沟,荒坡种植,通过引种俄罗斯大果,无刺沙棘优良品种与本地野生中国沙棘对比分析看,出,其适应性,抗性较中国沙棘差,经济性状较好,通过试验筛选出2种优良类型,果径为0.9-1.3cm,百果重46-52g,单株产果量2-3.5kg,无刺或少刺,此项研究为在半干旱黄土丘陵区大面积荒山,荒沟建造高产,优质沙棘林,高效,持续发展沙棘产业具重要意义,在引种试验中必须掌握好其关键技术,建立好采穗圃,种子园,并建立一定面积的集约经营的高产,优质沙棘园及良种繁育基地,掌握好抚育管理技术,特别是水,肥管理技术。     

不同小麦品种对播娘蒿的影响

播娘蒿是黄淮麦区主要田间杂草,在管理粗放的麦田,播娘蒿密度可达100株·ｍ-2以上,严重影响了小麦的产量和品质。因此,对小麦-杂草复合体中杂草的生长发育规律进行研究,寻找降低草害的有效途径引起许多学者极大关注[1,2],而目前有关防除麦田杂草的研究多集中于化学防治方面[3]。然而,出于环境保护和经济成本上的考虑,化学除草受到了挑战。研究人员[4,5]发现,不同物种在竞争力上存在差异,禾谷类作物属于竞争力很强的作物[6],冬小麦及冬黑麦又是其中竞争力最强的物种。就小麦栽培种而言,存在着不同的品种类型,研究不同小麦品种对杂草的抑制作…     

水稻品种和稻虱缨小蜂对褐飞虱协同作用的模拟分析

利用我们先前的试验结果和文献资料,组建了水稻品种－褐飞虱－稻虱缨小蜂３者相互关系的模拟模型．模拟分析表明水稻品种能直接和间接地通过物理或化学特性影响稻虱缨小蜂的寄生作用,其中以影响褐飞虱卵垂直分布型、稻虱缨小蜂的迁入时间、未成熟期历期和怀印量等的水稻品种特性起主要作用．同时,模拟分析还表明中等抗性的水稻品种,配以增强稻虱缨小蜂寄生作用的品种特性,就能有效地控制褐飞虱的危害．文中还就协调水稻品种抗性与天敌协同控制褐飞虱的途径进行了讨论．     

仙人掌科果类植物的品种及生产(综述)

仙人掌科的主要果类植物有５属１８个品种。本文重点介绍以红龙果为代表的柱形仙人掌果的繁殖、栽培与加工利用。     

小麦品种抗性对麦长管蚜种群增长的影响

本研究采用室内、外结合的方法,分苗期和拔节期,对大田抗蚜性鉴定中表现不同的10个小麦品种的抗性对麦长管蚜种群增长的影响进行了研究。研究结果显示,品种抗性对麦长管蚜的存活率、发育进度、繁殖力有一致的抑制作用;品种间抗蚜性存在显著差异。同时通过组建不同品种上麦长管蚜繁殖特征生命表,从量的角度揭示了小麦品种抗性与麦长管蚜种群增长之间的关系。     

茶叶中总硒含量及其影响因素的研究

茶叶中硒素总量测定结果表明：土壤含硒量的高低是直接影响茶叶中硒的总量。茶树根、茎、叶、果中均有硒元素,叶片是茶硒积累的主要器官,尤其是老叶,其含量是嫩叶的几倍．茶树品种间含量的差异显著,最大差异达10倍以上．毛茶加工的成品茶含硒量受加工技术措施影响较大,其不同等级的含硒量与级别没有线性关系．     

Worldwide distribution of commercial resources of seaweeds including Gelidium

The commercial exploitation of seaweeds for use as food and for the production of agar, alginate and carrageenan is outlined. The quantities of seaweed harvested for each purpose are tabulated and discussed. Seaweeds for food are derived chiefly from China, Japan and Korea, with almost 94% obtained by cultivation. Alginophytes are collected in 15 countries but six of these account for more than 80% of the total harvest; all are from natural stocks except for a large quantity of Laminaria cultivated in China. Natural carrageenophytes, from 12 countries, now account for only 20% of the total harvest; the remainder is cultivated Eucheuma species, 99% of which is produced in only two countries, the Philippines and Indonesia. Of the four categories of commercial resources of seaweeds considered, agarophytes are spread more evenly over a greater number of countries; they come from 20 countries and only five of these are minor contributors to the total. Gelidium species are particularly important because of the high quality agar they yield; their distribution and location are discussed.     

辽宁省番茄花叶病主要病毒和株系的研究

从辽宁南部及沈阳地区采集番茄花叶病样本111个(1985-1987),经鉴定得知主要毒原为番茄的烟草花叶病毒(TMV)占总调查的59.46％。黄爪花叶病毒(CMV)亦有发生仅占总调查的9.00％。还有一些系混合侵染(TMV和CMV)占21.62％。尚未认清毒原种的约占2.70％,接种无症的占7.20％。通过试验认为我省番茄上主要毒原为烟草花叶病毒,并进行了常规鉴定、提纯、电镜观察、光谱测定和血清测定等。对番茄上烟草花叶病毒16个分离物做了株系分化研究,按照Pelbam(1970,1972)〔14、15、16、17〕的抗性分类法应用番茄GCR一套品种接种观察,得知辽南及沈阳地区分布很广的番茄TMV分离物,均属TMV-O株系。故在番茄抗TMV育种中尚应考虑到抗1及2株系的能力。     

Field efficacy of Ceratitis capitata (Diptera: Tephritidae) mass trapping technique on clementine groves in Spain

Mass trapping is being used in Mediterranean regions to control Ceratitis capitata (Wiedemann) (Diptera: Tephritidae) in citrus. The technique is based on placing a high density of traps with an attractant (Ferag CC D TM^®, a three‐membrane dispensers of trimethylamine, ammonium acetate and diaminoalkane), and a toxicant, aiming to capture the highest numbers of adults in the grove. From 2006 to 2008, field trials were conducted in commercial Clementine (Citrus reticulata Blanco) groves to evaluate the efficacy against medfly of using different trap densities, 25, 50, 75 and 100 traps per ha. Based on the number of adults captured, fruit maturity parameters and medfly fruit damage, a 25 trap per ha density appears to be a valid stand‐alone method to protect mid‐season varieties (Clemenules) from the attack of C. capitata, because <0.5% of fruits on average were damaged at harvest. For early‐season varieties (Loretina and Marisol), mass trapping technique alone did not offer a satisfactory medfly control, because medfly populations were higher in the warmer months of the early‐season variety production, which led to a higher percentage of attacked fruits, even when increasing the trap density from 50 to 100 per ha. However, using 50 traps per ha density combined with chemical treatments only to the perimeter row of the grove gave good results, because <2% of fruits in average were damaged at harvest.