Influence of environmental factors on seed germination and emergence of Iresine diffusa
Influence of environmental factors on seed germination and emergence of Iresine diffusa
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DOI：
10.1111/wre.12114
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发表时间：
2014-12-01
期刊：
影响因子：
1.7
通讯作者：
Perreta, M. G.
中科院分区：
文献类型：
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作者：
Acosta, J. M.;Bentivegna, D. J.;Perreta, M. G.
在阿根廷免耕大豆种植下，白花鸢尾花的数量越来越多。通过生长室试验，研究了温度、光照、冷湿贮藏、渗透势、干燥贮藏和埋种深度对白花菊发芽和出苗的影响。在所有波动的昼夜温度下，白花草种子的发芽率最高（>0.80）。相反，在恒温条件下，15℃（0.78）和20℃（0.82）的发芽率最高，10℃（0.19）和30℃（0.36）的发芽率最低。光照对种子萌发没有影响。但在冷湿贮藏12周（0.76）和16周（0.65）后发芽率下降。为了显著降低种子萌发，需要-0.4MPa的渗透电位（PEG-6000诱导）或120mmol（-1）的盐（NaCl）浓度。经720d的干燥贮藏，白花菊的种子具有较高的活力（0.85）。埋在2cm处的种子出苗率较低，埋在5cm和10cm处的种子出苗率完全被抑制。白花鸢尾种子具有较高的生存力，能够在广泛的环境条件下萌发。白花菊萌发期的热萌发条件、浅土层深度和高水分条件与阿根廷免耕大豆基本一致。因此，免耕比常规耕作能提供更好的发芽条件。然而，由于白花金盏花可以通过根茎繁殖，因此需要进一步研究白花金盏花在田间存在和持续存在的过程中营养繁殖策略的相对重要性。
Iresine diffusa has become more abundant under no-till soyabean in Argentina. The influence of temperature, light, cold-wet storage, osmotic potential, dry storage and depth of seed burial on germination and emergence of I.diffusa was examined in a growth chamber experiment. Iresine diffusa seeds germinated at the highest proportion (>0.80) in all fluctuating day/night temperatures tested. Conversely, under a constant temperature regime, maximum germination rates occurred at 15 (0.78) and 20 degrees C (0.82), and minimum germination rates occurred at 10 (0.19) and 30 degrees C (0.36). Seed germination was not influenced by light exposure. However, germination decreased after 12 (0.76) and 16 (0.65) weeks in cold-wet storage. To reduce germination significantly, -0.4MPa of osmotic potential (induced by PEG-6000) or 120mmolL(-1) of salt (NaCl) concentration was required. Seeds of I.diffusa showed high viability (0.85) after 720days of dry storage. Low emergence was recorded for seeds buried at 2cm, and seedling emergence was completely inhibited when seeds were buried at 5 and 10cm. Iresine diffusa seeds had high viability and were capable of emerging in a broad range of environmental conditions. The thermal germination conditions, shallow soil depths and high moisture conditions in germination phase for I.diffusa are congruent with the conditions in Argentina no-tillage soyabean. Thus, no-tillage could provide better conditions for germination than conventional tillage systems. However, due to the fact that I.diffusa can reproduce by rhizomes, further research should be conducted to understand the relative importance of the vegetative reproductive strategy in relation to the presence and persistence of this weed in fields.