河流湿地灌木多刺锦鸡儿的种子萌发特性

Seed Germination Characteristics of Caragana spinosa from Floodplain

对青格里河湿地植物群落的优势种多刺锦鸡儿种子萌发对季节性昼夜温度变化、土壤含水量、原生境贮藏的响应进行研究,结果表明种子在不同变温(15℃/5℃、20℃/10℃、25℃/15℃、30℃/15℃、30℃/10℃、30℃/5℃)下的萌发率为74%~97%;种子萌发的最低土壤水分含量为1.25%,适宜萌发的土壤水分含量为3.75%~25%;种子在原生境贮藏期间萌发能力逐渐下降,至第2年夏季大部分种子失去萌发能力;取食多刺锦鸡儿种子的昆虫为刺槐种子小蜂,取食比率为15.9%。多刺锦鸡儿种子在生长季和不同土壤水分条件下可以萌发,但种子在原生境萌发能力失去以及被昆虫取食可能限制了其萌发,这是其种子途径更新的主要障碍。

Caragana spinosa(L.) DC., a forage shrub, is the dominant species in Qinggil floodplain of northwest China and a potential candidate species for vegetation restoration. In order to study the effects of daily temperature change, soil moisture and in situ storage on seed germination, and better understand the germination times of seeds, the germination characteristics of fresh and mature seeds after 12 h of alternate culture in Petri dishes were analyzed, under different temperatures of 15℃/5℃, 20℃/10℃, 25℃/15℃, 30℃/15℃, 30℃/10℃ and 30℃/5℃(day/night) and soil moisture of 0.5%~25%, fresh and mature seeds were stored in their natural habitat until the next year, exhumed three times and incubated at 25℃/15℃. The results showed that the germination rate of fresh seeds was 74% to 97% at different temperatures. The lowest soil moisture for germination was 1.25%. Optimum soil moisture for seed germination was 3.75% to 25%. The germination ability of seeds gradually decreased during in-situ storage, and most of seeds lost their vigor till next summer. 15.9% of the seeds were infested by insects, which is mainly involved with Bruchophagus philorobiniae. It implicated that seeds of C. spinosa could germinate at any time during the growing season when the soil moisture was sufficient. The inactivation of most seeds in the original habitat and insect feeding may be the main obstacles to seed regeneration of C. spinosa.