刺蒺藜草在我国的适生区预测

本研究基于MaxEnt模型,依据气候、海拔、人类活动等不同层面的12个环境变量建立刺蒺藜草适生性预测模型,模型AUC值高于0.9,表明模型结果可靠。预测显示：我国刺蒺藜草非适生区占73.66%;低度适生区占18.24%;中度适生区占5.11%;高度适生区占2.99%。其中广东、广西、海南几乎全境,福建、台湾、云南的大部分地区为中、高度适生区,具有最大的传入定殖风险。通过预测模型可以看出,bio＿11（最冷季度平均温度）、hf＿v3geo（人类足迹）、bio＿18（最暖季度降水量）和bio＿04（温度季节性变化标准差）等4个环境变量对刺蒺藜草在某地适生产生重要影响。     

Characterization for agronomic use of cytoplasmic male-sterility in sunflower (Helianthus annuus L.) introduced from H. resinosus Small

A backcrossing programme was carried out both to assess the stability of a cytoplasmic male‐sterility (CMS) source from Helianthus resinosus, designated RES1, and to incorporate it into inbred sunflower lines (HA89, RHA271, RHA801). All the progenies, grown in different environments, were completely male‐sterile. This suggests that the expression of this cytoplasm is stable. Female‐fertility of lines HA89, RHA271 and RHA801 carrying CMS RES1 were compared with those of the corresponding fertile inbred lines. There were no differences in the number of seeds per head. This indicates that female‐fertility is not affected by RES1 cytoplasm. Cytological studies showed that meiosis proceeds normally until the tetrad stage; consequently, the absence of pollen is caused by alterations that take place during postmeiotic stages. With the aim of identifying male‐fertility restorer genotypes, crosses were made between HA89 (CMS RES1) plants and different annual diploid and perennial hexaploid Helianthus species. All the diploid germplasm evaluated behaved as a CMS RES1 maintainer. However, the hexaploid species, H. resinosus, H. x laetiflorus, H. pauciflorus and H. tuberosus, restored pollen fertility in CMS RES1 plants.     

4种环境因子对少花蒺藜草(Cenchrus pauciflorus Benth.)种子萌发的影响

本试验以少花蒺藜草种子为研究材料,通过设定不同的温度、土壤湿度、土壤基质和光照等条件研究环境因子对少花蒺藜草种子萌发的影响.结果表明:少花蒺藜草种子萌发最适温度为25℃,萌发最低温度为20℃,萌发最高温度为30℃;光照对少花蒺藜草种子萌发有一定影响,光照促进种子萌发;土壤湿度对其萌发有影响,最适萌发湿度为20%,最低萌发湿度为6%;少花蒺藜草种子萌发对土壤基质要求不严格,于沙土及草炭土中均可萌发.     

Halophyte root powder: an alternative biofertilizer and carrier for saline land

ABSTRACT

The present investigation was based on the hypothesis that the endophytes residing in the roots of halophytes have better adaptation to saline conditions. Six halophytic herbs were collected from Khewra salt range (EC = 4.7 dS m^?1 and SAR = 25.7). From these herbs, root pieces of Cenchrus ciliaris were shade dried; finely ground to powder and three plant growth promoting rhizobacteria (PGPR), Bacillus cereus, Pseudomonad moraviensis, and Stenotrophomonas maltophilia, were isolated. Root powder in sterilized and unsterilized forms was added in the saline-sodic field on wheat and mixed with soil in pot experiment with induced NaCl (150 mM). Sterilized root powder increased organic matter NO₃-N and P contents of soil and leaves, fresh weight, sugar content, and yield attributes. The root powder application in unsterilized form significantly decreased EC, SAR, and Na content of field soil with concomitant increase in soil and leaves K, P, and NO₃-N. The farmer’s benefit was increased by 33% at yield. Root powder-induced salt tolerance was mediated by the PGPR (residing inside the root) through increased growth and better physiological adaptations. It is inferred that root powder harboring the PGPR may be an alternative to biofertilizer with longer shelf life and may also serve as carrier for the preparation of effective biofertilizer for saline land using other PGPR bio-inoculants.     

不同农作措施对少花蒺藜草(Cenchrus pauciflorus Benth)种子库及其繁殖能力的影响

系统调查了天然草原及旱作农田2种典型生境中少花蒺藜草种子库动态, 并深入研究了施肥、灌溉、刈割及替代种植对少花蒺藜草种群繁衍扩张的影响。结果表明:从2种生境土壤种子库中共鉴定出12科24属25种植物;天然草原及旱作农田少花蒺藜草种子总储量分别达12 923 粒·m^-2和8 960 粒·m^-2, 分别占整个种子库的67.72%及79.74%;天然草原生境中少花蒺藜草种子主要集中分布在土壤上表层(0~2 cm), 占种子总量的45.71%, 而旱作农田生境中, 少花蒺藜草种子在土壤表层(0~2 cm)、中层(2~5 cm)、下层(5~10 cm)中分布差异不显著(P>0.05)。试验也表明, 低施肥量能显著提高少花蒺藜草结实量(P<0.05), 而中、高水平施肥处理少花蒺藜草结实量反而降低;随着灌溉浇水量增加, 少花蒺藜草结实量显著增加(P<0.05), 高水平浇水量结实量平均为2 562.8 粒·株^-1;刈割能有效抑制少花蒺藜草种群种子繁殖, 每周刈割1次, 抑制少花蒺藜草结实率为97.69%;替代种植向日葵、菊芋能极显著抑制少花蒺藜草生长及结实量(P<0.01)。     

科尔沁沙地典型人工固沙林群落中少花蒺藜草入侵地土壤特性

对科尔沁沙地2个典型人工固沙林小叶杨(Populus simonii)和黄柳(Salix gordejevii)群落中优势种少花蒺藜草(Cenchrus pauciflorus)生境地土壤养分进行测定分析.结果表明:少花蒺藜草2生境地中土壤pH 值在7.35～7.80之间,土壤有机质含量在4.86～5.90 mg·kg^-1之间,碱解氮含量在21.4～59.07 mg·kg^-1之间,有效磷含量范围为 1.13～2.22 mg·kg^-1,速效钾含量在78.24～173.20 mg·kg^-1之间.土壤有机质及速效养分含量随着少花蒺藜草生长期的变化均有不同程度的下降,入侵地土壤沙化加重.     

基于转录组测序分析象草木质素合成的研究

采用高通量测序技术Illumlna HiSeq 2000对高木质素的象草品系eg7和低木质素的象草品系eg87(对照)茎组织进行转录组比较测序。测序获得了169630902个序列读取片段(reads),包含13788439920nt碱基信息。对reads进行序列组装,获得87641个单基因簇(unigene),平均长度580nt。从长度分布、GC含量等方面对unigene进行评估,数据显示测序质量好,可信度高。将获得的unigene与Nr、Nt、Swiss-Prot、COG、GO和KEGG数据库进行序列同源性比较和功能分析,62557个unigene与其他生物的已知基因具有不同程度的同源性,象草与高粱序列同源性最高。共鉴定出33323个差异表达基因,其中上调基因9704个(29.12%),下调基因23619个(70.88%);GO分析显示39968个unigene归为54个功能类别,大量unigene与细胞进程、代谢过程、催化活性等相关;KEGG pathway分析富集得到127条代谢通路,包括光合作用、betalain生物合成、苯丙烷类代谢、苯丙氨酸代谢等,苯丙烷类代谢途径差异基因富集程度高、差异基因数目最多,达285条,该途径中64条木质素单体合成酶基因表达上调,79条ClassⅢ型植物过氧化物酶基因表达下调、22条上调。挑选9个差异基因进行qRT-PCR验证,9个基因的表达趋势与高通量测序结果一致。为象草的分子生物学研究提供了宝贵的基因组数据,对于了解象草茎生物合成与木质素调控基因挖掘和多用途定向育种具有指导意义。     

High temperature effects on gas exchange for the invasive buffel grass (Pennisetum ciliare [L.] Link)

Buffel grass was introduced to the Sonoran Desert in the mid-twentieth century, where it has aggressively invaded new areas. Given its ecological success at a place where the air temperature can approach 50°C, the effects of high air temperatures on gas exchange were studied for this species. The carbon dioxide uptake and water use efficiency were maximal at day/night air temperatures of 30/20°C for potted plants, substantially decreasing at higher temperatures until the plants died at 45/35°C.     

乙草胺及其复配剂对少花蒺藜草的防除效果

由于长期缺乏对草原毒害草的重视,少花蒺藜草在彰武县全县范围内扩散蔓延,并已发展到难以控制的局面,给草原生态生产环境带来极大影响。本文通过喷施乙草胺单剂和乙草胺同精喹禾灵、烟嘧磺隆、烯草酮混合的3种复配剂来研究其对少花蒺藜草的防除效果。结果表明：喷施乙草胺单剂及其3种复配剂乙草胺+精喹禾灵、乙草胺+烟嘧磺隆、乙草胺+烯草酮40 d对少花蒺藜草均有较好的防治效果,防治效果都在75%以上。说明喷施乙草胺土壤处理剂及其和茎叶处理剂的复配剂可作为防除少花蒺藜草的手段之一,这对于草原上入侵生物少花蒺藜草的安全、有效防除有着重要意义。     

刈割对入侵植物少花蒺藜草再生生长及繁殖特性的影响

为探索有效控制辽西北风沙半干旱区恶性入侵植物少花蒺藜草(Cenchrus pauciflorus)扩散技术,在其严重侵染区开展不同时期刈割控制试验,结果表明,少花蒺藜草在整个生长季里均可保持较高的生长速率,刈割后具有超强的再生能力和明显的季节效应,其中分蘖期和拔节期刈割少花蒺藜草再生生长节律与自然生长的相一致,表现出快...