河西地区几种多年生栽培牧草的产量比较

通过对几种栽培饲草盛产期生产力水平试验,筛选出适宜河西地区高水肥条件下栽培的多年生饲草种类为松香草Silphium perfoliatum、紫花苜蓿Medicago sativa、百脉根Lotus corniculatus、无芒雀麦Bro-mus inermis,干草产量依次达到30 120、21 179、20 679和25 024 kg/hm2;粗蛋白产量分别达到6 174.6、5 083.4、4 756.2和2 628.0 kg/hm2,无氮浸出物达到8 478.4~11 911.4 kg/hm2。在河西地区每年刈割3茬产量最高,干草产量比刈割2茬提高7.4%~20.6%。鲁梅克斯Rumex acetosa、披碱草Elymus dahuricus高感白粉病和黑粉病,大面积栽培需要加强病害防治或更新抗病品种。     

宿根花卉的引种及抗性研究

宿根花卉为多年生草花,具有很多优点,在园林布置中占很重要的地位,实验通过对引种的18个品种抗寒性与抗旱性进行研究。结果表明,所有品种均有较强的适应性,可以用于呼和浩特当地种植。     

不同外植体对多年生黑麦草愈伤组织诱导的影响

对多年生黑麦草的3个品种进行愈伤组织诱导,选取成熟种子、成熟胚、胚轴、胚根4种外植体。结果表明,胚轴、胚根诱导效果较差,成熟胚在愈伤组织的诱导率、鲜重及愈伤质量方面均优于成熟种子。2,4-D浓度在2~4mg/L,6-BA浓度为0.025mg/L时有利于成熟胚诱导产生愈伤组织;成熟种子为外植体时,2,4-D浓度在5~8mg/L,6-BA浓度在0.025mg/L或0.2mg/L有利于成熟种子诱导产生愈伤组织。2,4-D浓度为2mg/L,6-BA浓度为0.5mg/L时成熟胚和成熟种子诱导的愈伤组织鲜重均达到最大。特拉华在愈伤组织的诱导率、增殖速度及愈伤质量方面表现较优,托亚次之,尤文图斯较差。AC和LH有利于植株的再生。     

黑龙江省野生宿根花卉资源及园林应用

黑龙江省地处寒温带,野生宿根花卉资源丰富。本文着重从其观赏特性、园林用途、配置原则等方面进行了综述,并提出合理开发利用建议。     

Advances in the Design of Resource-Efficient Cropping Systems

SUMMARY

Cropping systems in the Midwest USA are evolving as farmers seek labor-efficient designs to capture and use available light and precipitation. Heavy reliance on fossil fuels and other energy-intensive production inputs coupled with uncertain markets for commodities have encouraged the search for greater energy efficiency as well as alternative crops, markets, and production systems. Agroecology has emerged as an innovative and integrative approach to evaluating systems more suited to the often harsh and unpredictable environment, using native prairie structure and function as one guide to design of future systems. A more specific approach, Natural Systems Agriculture, is being explored as a new paradigm to saving soil while producing the crop and animal output needed for a growing global population. Whole-farm and landscape-level design and planning will become more important as society recognizes and values multifunctional rural landscapes.     

干旱胁迫对24种宿根花卉生长的影响

为探究干旱胁迫对不同宿根花卉生长的影响,通过盆栽控水方法测定24种宿根花卉在干旱胁迫下的株高、冠幅、根长及根冠比等生长指标,并根据各指标的旱水比值结合隶属函数法对其抗旱性进行初步排序。结果表明,干旱胁迫下所有试验材料的株高和冠幅均减小,根冠比和根长先增加后下降,抗旱性由强到弱依次为:马蔺>旱麦瓶草>菊叶委陵菜>‘金娃娃’萱草>二裂委陵菜>山麦冬>溪荪>叉分蓼>白屈菜>地被石竹>蓬子菜>蹄叶橐吾>蓝花棘豆>麻花头>展枝唐松草>华北蓝盆花>紫花耧斗菜>龙牙草>黄芩>草地风毛菊>地榆>路边青>‘小兔子’狼尾草>独活。     

Pasture or permanent crops after slash-and-burn cultivation? Land-use choice in three Amazon colonies

Land use was examined in three settlements – Pedro Peixoto in Acre and Theobroma in Rondonia, Brazil, and Pucallpa, in Peru. Research aimed at characterizing the differences in land use after initial slash-and-burn, and presenting hypotheses to assess the feasibility of improved land uses. Settlers in the Amazon practice slash-and-burn agriculture in forest lands to produce annual crops. After cropping, lands are converted to pasture, or planted with perennial crops, or fallowed in anticipation of future annual crop production. Land use after slash-and-burn cultivation in forest lands differed among the colonies examined. Whereas colonists in Pedro Peixoto converted lands to pasture for cattle production, settlers in Theobroma adopted a strategy encompassing both dual-purpose (milk and meat) cattle and perennial crop production. The more heterogeneous settlers in Pucallpa, who included small-scale cattle ranchers and riverine and forest slash-and-burn farmers, gave more importance to perennial crops. Hypotheses are suggested regarding the described land use differences, and implications for the adoption of agroforestry are discussed. This revised version was published online in June 2006 with corrections to the Cover Date.     

Are the duplicates of perennial kale (Brassica oleracea L. var. ramosa DC.) true duplicates as determined by RAPD analysis?

A collection of vegetatively propagated perennial kales (Brassica oleracea L. var. ramosa DC., 64 accessions in total), predominantly from the Netherlands, was subjected to RAPD analysis in order to confirm or reject the presence of possible duplicates as indicated by isozyme and cytological data, as well as by morphological data described here. By employing 9 decamer primers, seven RAPD patterns could be attributed to almost all of the respective accessions, with up to 22 clones exhibiting identical features for the parameters examined. By these results, a high percentage of duplication is very strongly indicated in the collection, offering possibilities for a reduction in the number of clones to be propagated. The highest level of genetic variation was found in two kales from Portugal, which differed significantly from the other accessions.     

高原地区多年生与一年生禾本科牧草混播效果

在高原地区退耕还草示范种植中,利用牧区广泛种植的一年生禾本科牧草燕麦Avena sativa与进口的多年生禾本科牧草细茎冰草Efymus trachycaulum混播。结果表明：燕麦和细茎冰草混播既能克服单一种植多年生禾本科牧草时的杂草危害问题,也能使退耕当年就获得较好的经济效益,解决了种植当年的收成问题,使项目建设的效益及早得到体现。第1年燕麦开花期鲜草产量为2.49 kg/m2, 细茎冰草第2年能够良好生长,第2年细茎冰草开花期鲜草产量为1.48 kg/m2,生长后期鲜草产量为1.76 kg/m2。     

Determination of Festuca filiformis seedbank characteristics,seedling emergence and herbicide susceptibility to aid management in lowbush blueberry (Vaccinium angustifolium)

Festuca filiformis is a common perennial grass in lowbush blueberry fields, but little is known about the general biology, seedbank characteristics, seedling recruitment or susceptibility of seedlings to currently registered herbicides. The objectives of this research were to determine (i) the presence of F. filiformis seedbanks in lowbush blueberry fields, (ii) whether F. filiformis seedbanks accumulate near the soil surface in lowbush blueberry fields, (iii) the dormancy status of fresh F. filiformis seeds, (iv) the temporal patterns of seedling recruitment in established F. filiformis populations, (v) whether F. filiformis has a vernalisation requirement for flowering in lowbush blueberry and (vi) susceptibility of F. filiformis seedlings to various herbicides currently registered in lowbush blueberry. Festuca filiformis formed a seedbank in lowbush blueberry fields, with an average of 1660 ± 272–5680 ± 1409 seedlings m^?2 emerging from soil cores collected from two infested fields. Most seeds were located at the soil surface, providing opportunities for seedbank management through predation or burning. Fresh seeds lacked dormancy and readily germinated, although germination was reduced by dark conditions. New seedlings emerged in spring and autumn and required vernalisation to flower. Seedlings were susceptible to several currently registered herbicides in lowbush blueberry, although mortality rates were highest in plants treated with glufosinate, flumioxazin, glufosinate + flumioxazin and terbacil. Growers should avoid movement of seeds on machinery, and additional research should be conducted to determine the effects of registered herbicides on F. filiformis seedling recruitment under field conditions in lowbush blueberry.