Cisgenesis,a New Tool for Traditional Plant Breeding,Should be Exempted from the Regulation on Genetically Modified Organisms in a Step by Step Approach

Modern potato breeding requires over 100,000 seedlings per new variety. Main reasons are (1) the increasing number of traits that have to be combined in this tetraploid vegetatively propagated crop, and (2) an increasing number of traits (e.g., resistance to biotic stress) originates from wild species. Pre-breeding by introgression or induced translocation is an expensive way of transferring single traits (such as R-genes, coding for resistance to biotic stress) to the cultivated plant. The most important obstacle is simultaneous transfer of undesired neighbouring alien alleles as linkage drag. Stacking several genes from different wild sources is increasing this linkage drag problem tremendously. Biotechnology has enabled transformation of alien genes into the plant. Initially, transgenes were originating mainly from microorganisms, viruses or non-crossable plant species, or they were chimeric. Moreover, selection markers coding for antibiotic resistance or herbicide resistance were needed. Transgenes are a new gene source for plant breeding and, therefore, additional regulations like the EU Directive 2001/18/EC were developed. Because of a strong opposition against genetic modification of plants in Europe, the application of this Directive is strict, very expensive, hampering the introduction of genetically modified (GM) crops and the use of this technology by small and medium-sized enterprises (SMEs). Currently, GM crops are almost the exclusive domain of multinationals. Meanwhile, not only transgenes but also natural genes from the plant species itself or from crossable plant species, called cisgenes, are available and the alien selection genes can be avoided in the end product. This opens the way for cisgenic crops without alien genes. The existing EU directive for GM organisms is not designed for this new development. The cisgenes belong to the existing breeders’ gene pool. The use of this classical gene pool has been regulated already in agreements regarding breeders’ rights. We are proposing a step by step approach starting with a crop and gene specific derogation and monitoring towards a general exemption of cisgenic plants from the Directive. Two examples, i.e. development of cisgenic potato for resistance to Phytophthora infestans and cisgenic apple for resistance to Venturia inaequalis are discussed shortly for illustration of the importance of cisgenesis as a new tool for traditional plant breeding. Cisgenesis is simplifying introgression and induced translocation breeding tremendously and is highly recommended for SMEs and developing countries.     

滴施不同比例的K_2SO_4/KCl对马铃薯生长的影响

[目的]为马铃薯生产中高效合理利用钾肥提供理论依据。[方法]在盆栽试验条件下,通过滴灌施肥系统滴施钾肥,探讨不同比例的K2SO4/KCl对马铃薯生长、产量和品质的影响。[结果]在试验条件下,滴施K2SO4和滴施K2SO4/KCl比例为1∶1处理有利于马铃薯植株生物量的积累;滴施KCl处理和滴施K2SO4/KCl比例为1∶1处理马铃薯块茎产量显著高于其他3个处理马铃薯块茎产量,比滴施K2SO4处理增产10.1%～13.6%;滴施KCl有利于马铃薯块茎对钾的累积,而滴施K2SO4更有利于提高马铃薯的淀粉含量。[结论]在马铃薯生产中,滴施KCl或在滴施KCl时配施一定比例的K2SO4有较好的增产作用。     

不同覆盖方式对冬闲稻田马铃薯生长及产量的影响

在冬闲稻田里以中薯3号为试验材料，进行了稻草覆盖、摆播稻草+地膜覆盖、沟播稻草+地膜覆盖、地膜覆盖、敞土等不同覆盖方式栽培马铃薯的田间比较试验。结果表明：冬闲稻田地膜覆盖栽培的马铃薯出苗最早，地膜覆盖和沟播稻草+地膜覆盖栽培的马铃薯出苗率最高；敞土栽培的马铃薯植株的株高显著低于覆盖栽培；摆播或沟播稻草+地膜覆盖栽培马铃薯的产量和商品薯率最高，稻草覆盖栽培和地膜覆盖栽培次之，产量和商品薯率显著高于敞土栽培；摆播或沟播稻草+地膜覆盖栽培马铃薯的效益最高，地膜覆盖和稻草覆盖栽培马铃薯的效益次之，敞土栽培马铃薯的效益最低。     

湖北省秸秆和畜禽粪污还田化肥替减潜力与环境承载力分析

湖北省畜禽业规模化养殖水平显著提高,秸秆资源量逐年提升,农业废弃物还田不仅可以减少农业面源污染,还可以减少化肥施用。该研究将湖北省分为5个种植区域(即鄂东南低山丘陵区、鄂北低山丘岗区、鄂西北山地区、鄂中平原区以及鄂西南山地区)。基于2019年-2020年统计数据,收集不同区域主要畜禽(猪、肉牛、奶牛、羊、肉鸡、蛋鸡)的存栏量、出栏量以及饲养周期,主要农作物种植面积和经济产量,计算湖北省畜禽粪污的养分供给量,评估不同区域的畜禽养殖现状是否超过土地承载畜禽粪污的最大容许数量。根据不同农作物的草谷比以及秸秆养分含量,计算出湖北省农作物秸秆的养分资源量以及养分还田量。湖北省不同区域畜禽养殖量均未超出当地最大承载容纳量,其中鄂北地区的土地承载力指数最高,达到了0.35～0.78,鄂中地区的土地承载力指数仅在0.17～0.54,有较大的空间来发展畜禽养殖业。2019年湖北省畜禽粪污养分资源量分别为36.89万tN、14.03万t P₂O₅、52.06万tK₂O。按照畜禽粪污肥料化还田率65%计算,畜禽粪肥的养分还田总量分别为23.9...     

几种水蚀阻断措施对坡地红壤干旱的影响

通过田间试验,研究了带状牧草、稻草覆盖和聚丙烯酰胺(PAM)表施及其组合措施对坡地红壤0-45cm土层干旱的影响。结果表明,各种水蚀阻断措施都能明显提高坡地红壤表层的土体贮水量;措施之间保水效果的差异在多雨阶段较小,而干旱阶段较大,且随土层深度增加而变大;水蚀阻断措施能够降低土体干旱发展速度,减轻土壤干旱,从而减轻作物干旱,增加其产量;PAM表施和稻草覆盖的保水抗旱效果要明显好于带状牧草。PAM表施、稻草覆盖分别与带状牧草组合以后,保水效果都有所减弱。     

外源钙对盐胁迫下马铃薯试管苗生长和相关生理特性的影响

采用组织培养方法,研究了外源硝酸钙对盐胁迫(100mmol/L NaCl)下马铃薯试管苗生长及相关生理指标的影响。结果表明:盐胁迫下试管苗生物量显著下降,叶绿素质量分数、根系活力和抗氧化酶活性显著降低,脂质过氧化指标丙二醛(MDA)质量摩尔浓度显著增加,试管苗生长受抑制;适量的硝酸钙(10mmol/L)能在一定程度上缓解盐胁迫对马铃薯试管苗生长的抑制,提高根系和叶片中超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和过氧化物酶(POD)的活性,使之维持在较高的水平,降低MDA质量摩尔浓度和细胞膜透性,增强根系活力及增加试管苗叶绿素质量分数。可见,适量的外源钙可通过促进盐胁迫下试管苗内抗氧化酶活性的提高,降低膜脂过氧化水平,增强光合能力,缓解盐害对马铃薯试管苗生长的抑制作用,诱导其耐盐性的提高。     

马铃薯脱毒小薯雾培结薯特点及增产效果

 采用草炭+ 蛭石双层基质无土栽培和自动控制槽式喷雾栽培两种模式进行马铃薯脱毒小薯结薯数量及小薯质量分布比较, 同期定植, 结果表明70 d 生长期内前者每株匍匐茎数量为15 条, 膨大成薯5. 7 个, 后者匍匐茎数量为97 条, 膨大成薯76 个, 分别是前者的6. 5 倍和13. 3 倍。槽式雾培较基质无土栽培可显著提高脱毒小薯的繁殖系数。     

双垄全膜覆盖沟播栽培条件下马铃薯品种比较试验

双垄全膜覆盖沟播栽培技术改善了农田生态系统,特别是土壤水分条件,有利于马铃薯的生长和发育,为了选择适宜于双垄全膜覆盖沟播栽培技术的马铃薯品种,获得更高的产量和经济效益。为此,在神林乡叶河村进行马铃薯品比试验,为选择适宜双垄覆盖栽培技术的马铃薯品种提供科学依据。     

固原市马铃薯晚疫病发生程度与环境因子关系分析

2011年通过田间病情消长调查,应用比利时马铃薯晚疫病预警系统分析了固原市马铃薯晚疫病发生程度与各环境因子的关系。结果表明,马铃薯晚疫病始见期迟早与发生程度无正相关关系,高湿有利于发病,但高温可抑制发病。利用比利时马铃薯晚疫病预警系统预测的结果与大田发生蔓延情况基本吻合。     

不同气候因子条件下影响马铃薯淀粉含量的因素分析

［目的］为各区域调整马铃薯的种植结构提供理论依据。［方法］通过测定不同气候因子条件下各种植区域主要马铃薯品种的淀粉含量,分析了马铃薯淀粉含量的影响因素。［结果］不同马铃薯品种平均淀粉含量的变异系数在1.56～17.95。不同年份间各品种淀粉含量的变异系数由大到小依次为武薯8号＞夏波蒂＞LK99＞大西洋＞陇薯6号＞渭薯8号＞陇薯5号＞新大坪＞陇薯3号＞大白花。各级别块茎的淀粉含量变异系数由大到小依次为渭薯8号＞宁薯4号＞陇薯7号＞武薯8号＞庄薯3号＞陇薯5号＞陇薯3号＞甘农薯1号＞大白花＞新大坪＞陇薯6号。陇薯5号、庄薯3号、武薯8号、渭薯8号的小块茎淀粉含量高于其大、中块茎,分别达16.82%、17.34%、18.17%和17.07%。［结论］该研究为制定不同区域、不同品种马铃薯的标准化栽培管理技术规程奠定了基础。