我国水稻田稗属杂草种类分布特点：以9个省级行政区73个样点调查数据为例

【目的】明确我国水稻田发生危害的稗属(Echinocloa spp.)杂草种类分布特点。【方法】2015年至2018年间的9月至11月,在东北、华东、华南、西北、西南水稻产区依据《中国植物志》英文修订版的分类鉴定标准,于水稻收割前采用七级目测法调查了73个地点共525块稻田稗属杂草的发生情况。【结果】共发现8种稗属杂草,其中无芒稗(E. crusgalli var. mitis)的发生频度最大(55.43%),其次是硬稃稗(E. glabrescens, 47.28%)、稗原变种(E. crusgalli var. crusgalli,40.40%)、西来稗(E. crusgalli var. zelayensis,24.09%);长芒稗(E. caudate)、水田稗(E. oryzoides)、孔雀稗(E. cruspavonis)、光头稗(E. colona)的频度较低。东北地区稻田稗属杂草以水田稗为单优势种;华东地区稻田稗属杂草呈现共优势的格局,硬稃稗、无芒稗危害最重,西来稗、稗原变种发生量也较大;华南地区稻田以稗原变种为单优势种;西北地区稻田无芒稗和稗原变种为优势种;西南地区稻田无芒稗占优势,稗原变种危害频繁。在这8种水稻田常见稗属杂草中,无芒稗的生态位宽度值最大(35.2),其次是硬稃稗(23.6)、西来稗(18.2)和稗原变种(16.3)。无芒稗、硬稃稗、西来稗相互之间的生态位重叠值较高,稗原变种与孔雀稗、光头稗、长芒稗的重叠值也较高。【结论】我国不同地区具有不同的稻田稗属杂草种类分布格局,其背后的机理亟待研究阐明。

Distribution Characteristics of Echinocloa Species in Rice Fields in China: A Case Survey on 73 Sites from Nine Provincial Administrative Regions

【Objective】The purpose is to disclose the distributon patterns of Echinocloa species in rice fields in China. 【Method】In periods from September to November between 2015 and 2018, we conducted field surveys on the occurrence of Echinocloa species at 73 locations (totally 525 rice fields). 【Result】Totally eight Echinocloa species were observed in the 525 fields surveyed. Among these fields, E. crusgalli var. mitis showed the highest frequency (55.43%), followed by E. glabrescens (47.28%), E. crusgalli var. crusgalli (40.40%), E. crusgalli var. zelayensis (20.94%); and E. caudata, E. oryzoides, E. cruspavonis, E. colona showed low frequency. On rice fields surveyed in Northeast China, E. oryzoides was mono-dominant among Echinocloa species on rice fields; in East China, E. glabrescens and E. crusgalli var. mitis were the most serious among this genus, E. crusgalli var. crusgalli and E. crusgalli var. zelayensis also showed high occurrences; in South China, E. crusgalli var. crusgalli was mono-dominant; in Northwest China, E. crusgalli var. mitis and E. crusgalli var. crusgalli were dominant; and in Southwest China, E. crusgalli var. mitis was dominant and E. crusgalli var. crusgalli also showed high occurrence. Among the eight Echinocloa species observed, E. crusgalli var. mitis showed the highest niche breadth (35.2), followed by E. glabrescens (23.6), E. crusgalli var. zelayensis (18.2) and E. crusgalli var. crusgalli (16.3). Niche overlaps among E. glabrescens, E. crusgalli var. zelayensis and E. crusgalli var. mitis were high, as well as those between E. crusgalli var. crusgalli and E. cruspavonis, E. colona or E. caudata, respectively.【Conclusion】Frequency of Echinocloa species varied with areas, and the relative mechanisms entail further studies.