魔芋的组织培养和工厂化生产技术

概述了国内魔芋组织培养技术的发展历程和现状,为魔芋试管苗、试管芋、脱毒种芋的工厂化提供了参考。     

魔芋无土栽培营养液配方研究初报

分别采用全MS、1/2MS、1/5MS、1/10MS(含大量元素、微量元素和铁盐)、1/10MS大量元素营养液(不含微量元素和铁盐)定期浇灌用蛭石栽培的不同级别的魔芋,前50d生长状况没有差异,50-80d以1/2MS-1/10MS营养液为佳,80-110d时1-5MS-1/10MS生长较好;魔芋在缺乏微量元素的营养液中后期生长不良,提前倒苗;产量分析结果表明:35g以上的种芋以1/2MS最高,35g以下的种芋以1/10MS最高,魔芋的耐盐浓度在2.25‰以下,高盐浓度对块茎的形成有毒害作用,造成产量大幅度下降,添加微量元素和铁有较好的增产作用。     

魔芋试管芋营养液栽培生产原原种技术研究

在温室对魔芋试管芋立体多架层营养液栽培生产原原种技术进行了研究。以不同质量分数和比例的N、P、K、Ca、Mg等大量元素和MS培养基的微量元素配制成营养液,对魔芋试管芋进行立体多架层无土栽培试验,结果表明:生长状况和原原种的产量均以N∶P∶K∶Ca:Mg的比例为4∶1∶2.4∶0.2∶0.7的Ⅴ号营养液最高,光照强度以2000~6000 Lux为宜。该试验为魔芋营养液的配方研制及栽培管理技术提供了理论依据。     

魔芋良种繁育技术体系建设概况

概述了魔芋良种繁育技术体系建设的发展历程,重点介绍了魔芋种芋的三级繁育体系、根状茎两年速成法和(试管芋)二年速成良种繁育技术,为魔芋产业发展中成果的转化应用起到了引导作用.     

魔芋微型试管芋(拟球茎)繁殖技术研究

在魔芋愈伤组织的基础上,研究了培养基组成、培养条件等因素对试管芋形成的影响。魔芋愈伤组织在添加6-BA3.0 mg.L-1、NAA0.5 mg.L-1、IBA0.5 mg.L-1、KT5.0 mg.L-1的MS培养基上,20 d后形成大量不定芽。待不定芽生长至约0.5~1 cm时,将温度控制在15~20℃之间,不定芽基部膨大,2个月后形成多达10个以上的微型种芋,种芋之间以愈伤组织相连。将微型种芋连同愈伤组织取出,栽培到适当的基质中,浇灌营养液使基质保持湿润,自然条件下萌发,出苗率在90%以上,叶片多达18片,当年每块微型种芋可形成5 g以上的多个子芋。     

魔芋无土栽培营养液配方研究初报

分别采用全MS、1／2MS、1／5MS、1／10MS(含大量元素、微量元素和铁盐)、1／10MS大量元素营养液(不含微量元素和铁盐)定期浇灌用蛭石栽培的不同级别的魔芋,前50d生长状况没有差异,50～80d以1／2MS～1／10MS营养液为佳,80～110d时1／5MS～1／10MS生长较好;魔芋在缺乏微量元素的营养液中后期生长不良,提前倒苗;产量分析结果表明：35g以上的种芋以1／2MS最高,35g以下的种芋以1／10MS最高,魔芋的耐盐浓度在2．25％。以下,高盐浓度对块茎的形成有毒害作用,造成产量大幅度下降,添加微量元素和铁有较好的增产作用。     

魔芋组培良种繁育技术体系新进展

介绍了近年来魔芋组培良种繁育技术体系建设研究中的多项成果,主要魔芋组培原原种工厂化生产技术、种芋包衣技术、质量监控技术和大田栽培配套技术等一系列关键技术研究方面的进展,为魔芋产业发展中成果的转化应用起到了支撑作用.     

氨基酸-硒、铜配合物对魔芋软腐病的防治效果研究

分别用24种氨基酸-硒、铜配合物对魔芋种芋进行浸种处理,栽培后观察魔芋的生长状况和软腐病的发生情况。结果表明:复合氨基酸中,3AA-Na2SeO3、3AA-CuSO4、15AA-CuSO4、17AA-Na2SeO3、17AA-CuSO4、单个氨基酸中精氨酸-Na2SeO3、脯氨酸-Na2SeO3、赖氨酸-CuSO4可提高植株的抗性,降低软腐病的发病率;丙氨酸-CuSO4、蛋氨酸-Na2SeO3处理的魔芋平均产量最高;甘氨酸-CuSO4、精氨酸-Na2SeO3处理最大单个重量最高。从软腐病发病率和产量两个方面来说精氨酸-Na2SeO3处理效果最好。     

影响芋茎尖培养中脱毒和快速繁殖的几个生理因素

以3个芋品种（‘石川早生’、‘虾籽芋’、‘叶用芋）球茎茎尖为外植体,进行脱病毒和快繁的结果表明,外植体表面灭菌的最佳方法是剥鳞片→乙醇→新洁尔灭→剥幼叶→氯化汞;适宜茎尖分化的培养基为MS＋1．0-2．0mg·L^-16-BA＋0．2mg·L^-1 NAA。生物学方法和电镜观察显示：连续3代0．5-0．7mm茎尖剥离培养对芋花叶病毒（DMV）的脱毒率达100％。在培养基MS＋0．2mg·L^-1 NAA中,适量添加6-BA和TDZ,三品种芋的试管苗增殖效果好;附加KT,试管苗生长健壮且利于生根：添加20-100mg·L^-1的精胺（spm）,可促进不定芽的发生,与KT配合使用可促使继代增殖和成苗一步完成。完整植株在草炭土：蛭石=1：1的基质中,移栽成活率超过97％,且苗生长健壮。     

紫薯提取物对花叶芋试管苗生长的影响

实验以花叶芋无菌苗为材料,通过研究有机提取物种类,提取物浓度及提取物提取方式对花叶芋试管苗生长的影响,筛选出最适合花叶芋试管苗培养的天然有机提取物。实验结果表明：MS基本培养基中添加紫薯提取物时,花叶芋试管苗生长优于其他植物提取物;当紫薯提取物浓度为10％时,花叶芋试管苗长势最佳;比较紫薯上清液、沉淀物、混合液3种提取方式,紫薯混合液对花叶芋的生长最为有利。     

The effect of irrigation on powdery scab and other tuber diseases of potatoes

In field experiments seed tubers affected with powdery scab cankers were planted and the effect on disease incidence of timing of irrigation and some seed-tuber fungicides was investigated over 3 yr. For 2 yr, irrigation to maintain soil wetter than—20 centibars (—20 kPa) during the first half of the growing season increased disease compared to unirrigated plots. Disease incidence was not affected by irrigation at 2 wk intervals or when applied during the second half of the season. Little disease developed in 1983 even in irrigated plots, probably because of high soil temperatures. None of the fungicides tested gave consistent disease control. Common scab and silver scurf were both decreased by irrigation but in two years, black dot was increased. The relative importance of black dot could increase in irrigated crops where fungicides are used to control silver scurf.     

Inoculation of seed-borne fungus in the rhizosphere of Festuca arundinacea promotes hydrocarbon removal and pyrene accumulation in roots

Background and aims

The selective inoculation of specific hydrocarbon-degrading microbes into the plant rhizosphere offers a useful means for remediating hydrocarbon-contaminated soils. The effect of inoculating a seed-borne filamentous fungus (Lewia sp.) on hydrocarbon removal by Festuca arundinacea and its growth was studied on perlite (model soil) and soil, both spiked with hydrocarbons.

Methods

A hydrocarbon mixture (1,500 mg kg^?1) of two polycyclic aromatic hydrocarbons (PAH), phenanthrene and pyrene, blended with hexadecane (1.0:0.5:0.5 weight) was used. Greenhouse experiments were carried out for 45 days. Inoculated and non-inoculated plants were grown in dark cylindrical glass pots containing perlite or soil.

Results

Inoculation with Lewia sp. stimulated (100 %) root growth in spiked perlite. Inoculated plants showed higher phenanthrene removal (100 %) compared to non-inoculated plants in perlite and soil. Pyrene removal by inoculated plants was 37-fold higher than that by non-inoculated plants in perlite; in soil, pyrene removal by inoculated plants (97.9 %) differed significantly from that of non-inoculated plants (91.4 %). Accumulation of pyrene in roots (530.9 mg kg^?1 of dry roots) was promoted in perlite.

Conclusions

Our results demonstrate that Lewia sp. (endophytic fungus) improved the efficiency of PAH removal by F. arundinacea, on both perlite and soil, stimulating pyrene accumulation in roots.     

黄土丘陵区三种典型土壤地类造林技术

中国黄土高原丘陵沟壑区是世界上水土流失最严重的区域之一,由于长期水土流失的侵蚀切割作用,表层土壤流失殆尽,黄绵土母质、红胶泥土以及土壤与岩石过渡类型--风化岩沫土等土壤类型依次裸露了出来,形成了3种典型的土壤地类,增加了造林的难度.由于红胶泥与风化岩沫土土壤瘠薄,当地林业部门认为这两种土壤地类不能造林,因此,传统造林只在黄棉土进行.为此,提出了＂适土适树,因土制宜＂的造林原则和＂穴衬膜栽植技术＂,以扩大适宜造林的土壤类型.穴衬膜栽植技术是指树木栽植时,在挖好的栽树坑底部和四周衬贴一层防渗薄膜（厚度为0.0007 mm可降解塑料薄膜）,树木栽好覆土浇水后,再在地表面覆膜,防止栽树浇水（施肥）的渗漏和蒸发,使树根在较长时间内处于含水量较高、四周封闭的潮湿土壤之中,从而达到提高成活率和促进林木前期生长的目的.1997～2001年,我们在黄土丘陵区陕西省延安市下砭沟小流域采用田间对比试验法进行了5年试验,结果表明,穴衬膜栽植技术促进浅层根系的生长发育,保水作用可持续4个月以上,对各种树木成活率和生长量均有显著促进作用,在黄土丘陵地区这3种土壤地类采用穴衬膜栽植技术可达到良好的造林效果,特别是红胶泥和风化岩沫土地类主要位于沟谷两岸,地下水供给较为充裕,是浅根性植物生长发育的良好土壤类型,科学混交可获得更好效果.     

半干旱黄土区苜蓿草地轮作农田土壤氮、磷和有机质变化

大田试验研究了多年生苜蓿草地轮作农田2年内的耕层土壤氮、磷养分和有机质变化.结果表明,与苜蓿连作相比,苜蓿草地轮作成农田后,土壤N和有机质消耗增加,2年中耕层土壤全氮含量平均分别下降了5.4%和19.5%、有机质下降了46.8%和28.2%,土壤全磷无显著变化;轮作提高了土壤氮、磷养分有效性及其活化率,土壤硝态氮含量2年分别提高了15.5%和159.1%、速效磷含量提高了44.5%和48.0%,差异显著.不同轮作方式对土壤养分变化有显著影响.苜蓿草地轮作后第2年,种植春小麦与种植玉米相比差异显著,种植马铃薯和休闲处理土壤养分变化幅度处于二者之间.种植春小麦能够维持农田土壤肥力生长季平衡,种植玉米增加了对土壤全氮、有机质和速效磷的消耗,土壤养分含量出现季节性下降,C/N和C/P降低.在半干旱地区多年生苜蓿草地向农田转变过程中,以轮作春小麦为宜,应避免种植玉米作物,以维持农田肥力平衡.     

Effects of litter addition on ectomycorrhizal associates of a lodgepole pine (Pinus contorta) stand in Yellowstone National Park

Increasing soil nutrients through litter manipulation, pollution, or fertilization can adversely affect ectomycorrhizal (EM) communities by inhibiting fungal growth. In this study, we used molecular genetic methods to determine the effects of litter addition on the EM community of a Pinus contorta stand in Yellowstone National Park that regenerated after a stand-replacing fire. Two controls were used; in unmodified control plots nothing was added to the soil, and in perlite plots perlite, a chemically neutral substance, was added to maintain soil moisture and temperature at levels similar to those under litter. We found that (i) species richness did not change significantly following perlite addition (2.6 +/- 0.3 species/core in control plots, compared with 2.3 +/- 0.3 species/core in perlite plots) but decreased significantly (P < 0.05) following litter addition (1.8 +/- 0.3 species/core); (ii) EM infection was not affected by the addition of perlite but increased significantly (P < 0.001) in response to litter addition, and the increase occurred only in the upper soil layer, directly adjacent to the added litter; and (iii) Suillus granulatus, Wilcoxina mikolae, and agaricoid DD were the dominant organisms in controls, but the levels of W. mikolae and agaricoid DD decreased significantly in response to both perlite and litter addition. The relative levels of S. granulatus and a fourth fungus, Cortinariaceae species 2, increased significantly (P < 0.01 and P < 0.05, respectively) following litter addition. Thus, litter addition resulted in some negative effects that may be attributable to moisture-temperature relationships rather than to the increased nutrients associated with litter. Some species respond positively to litter addition, indicating that there are differences in their physiologies. Hence, changes in the EM community induced by litter accumulation also may affect ecosystem function.     

条带休闲轮种对坡地水土流失和水分利用效率的影响

为提高宁南旱区坡耕地土壤保水能力、减少水土流失,于2007-2010年在10°～15°坡耕地上,以传统无条带种植模式为对照,研究条带隔年休闲轮种模式对农田土壤水分动态、水土流失特征和水分利用效率的影响.结果表明:经过4年休闲轮种,条带处理比传统无条带种植处理显著增加0 ～200 cm土层土壤含水量4.9％～7.0％;条带轮种比无条带模式有效保蓄雨季休闲期降水,明显改善了作物生育前期的土壤水分状况,条带处理0～200 cm土层土壤含水量比对照显著增加5.4％～8.5％.与对照相比,条带休闲轮种处理地表径流减少0.7 ～3.2 m3·hm-2,泥沙量减少0.2～1.9 t·hm-2,土壤全N损失量减少42.1％ ～73.3％,作物水分利用效率提高6.1％ ～24.9％,降水利用效率提高6.3％ ～15.3％.     

Effects of Litter Addition on Ectomycorrhizal Associates of a Lodgepole Pine (Pinus contorta) Stand in Yellowstone National Park

Increasing soil nutrients through litter manipulation, pollution, or fertilization can adversely affect ectomycorrhizal (EM) communities by inhibiting fungal growth. In this study, we used molecular genetic methods to determine the effects of litter addition on the EM community of a Pinus contorta stand in Yellowstone National Park that regenerated after a stand-replacing fire. Two controls were used; in unmodified control plots nothing was added to the soil, and in perlite plots perlite, a chemically neutral substance, was added to maintain soil moisture and temperature at levels similar to those under litter. We found that (i) species richness did not change significantly following perlite addition (2.6 ± 0.3 species/core in control plots, compared with 2.3 ± 0.3 species/core in perlite plots) but decreased significantly (P < 0.05) following litter addition (1.8 ± 0.3 species/core); (ii) EM infection was not affected by the addition of perlite but increased significantly (P < 0.001) in response to litter addition, and the increase occurred only in the upper soil layer, directly adjacent to the added litter; and (iii) Suillus granulatus, Wilcoxina mikolae, and agaricoid DD were the dominant organisms in controls, but the levels of W. mikolae and agaricoid DD decreased significantly in response to both perlite and litter addition. The relative levels of S. granulatus and a fourth fungus, Cortinariaceae species 2, increased significantly (P < 0.01 and P < 0.05, respectively) following litter addition. Thus, litter addition resulted in some negative effects that may be attributable to moisture-temperature relationships rather than to the increased nutrients associated with litter. Some species respond positively to litter addition, indicating that there are differences in their physiologies. Hence, changes in the EM community induced by litter accumulation also may affect ecosystem function.     

陕西渭北柿子园种植白三叶草对土壤养分和生物学性质的影响

种植豆科绿肥可以有效增加氮肥来源,提高水土保持能力,改善生态环境与土壤质量,是促进农业生产可持续发展的重要措施之一.本试验研究了柿子园种植白三叶草对土壤养分和生物学性质的影响,以探明果园种植豆科绿肥在土壤肥力改良与经济效益提升方面的潜力.设柿子园清耕、种植白三叶草2个处理,于2017年9月14日分别采集0～10、10～20、20～30和30～40 cm土层样品,以分析两个处理对土壤有机质、速效氮、微生物生物量碳、氮和酶活性的影响.结果表明: 与清耕相比,生草后的整个被测土层的有机质、速效氮、微生物生物量碳、氮及脲酶、蔗糖酶、过氧化氢酶、碱性磷酸酶活性均增加,其中,0～10 cm土层生草处理的有机质、微生物生物量碳增加效果显著,10～20 cm土层速效氮含量增加效果显著,0～20 cm土层中脲酶活性显著增加,而过氧化氢酶活性、蔗糖酶及土壤酶活性的几何平均值(GME)则在整个被测土层都显著增加.表明果园生草能改善土壤肥力状况,在一定程度上可减少化肥氮投入量,提高果园经济效益,是一种优良的果园栽培模式.     

酸性硫酸盐土水改旱后土壤化学性状的变异初报

探讨了酸性硫酸盐水稻土改为旱作后土壤化学性状的变异以及比较不同利用方式之间的经济效益．结果表明,酸性硫酸盐水稻土改种甜玉米和蔬菜后,土壤化学性状发生显著变化．耕层土壤酸度、水溶性硫酸根含量、土壤活性铝和活性铁含量均显著降低．经济效益得到显著提高．建议对水改旱后的环境效应进行深入研究以及进行定位观测,以便合理利用这一特殊的土壤资源     

覆盖作物的种植现状及其对下茬作物生长和土壤环境影响的研究进展

覆盖作物指的是在农业生产间隙种植,使土壤在时间或空间上减少或避免裸露的一种作物。其能使农田土壤免受风蚀、水蚀和人为扰动的影响,被认为是一种新型的保护性耕作方式。本文简要介绍了农田覆盖作物的种植管理情况,包括种植品种、耕作模式和绿肥作物的灭生还田方式等,可为推广覆盖作物在农田休闲期的高效大面积种植提供参考。基于国内外研究综述了绿肥种植对经济作物、土壤质量、杂草抑制、温室气体排放和土壤微生物等的影响及研究进展,阐明了覆盖作物对农田生态系统的诸多益处。尽管覆盖作物存在局限性,例如短期收益不明显、管理措施不当会造成作物减产等,但其在改善土壤质量、实现农业可持续发展方面仍然具有重要的应用价值。