西(xi)瓜(gua)種(zhong)子(zi)在催芽(ya)過程中(zhong)，有(you)時會(hui)出現(xian)種(zhong)皮從發(fa)(fa)芽(ya)孔(kong)（種(zhong)子(zi)嘴）處開口，甚(shen)至(zhi)整個種(zhong)子(zi)皮張開的(de)現(xian)象。種(zhong)皮開口后，水分(fen)浸入易造(zao)成槳種(zhong)（種(zhong)仁(ren)腫水而發(fa)(fa)酵）、爛種(zhong)、胚根不能(neng)伸(shen)長等，即便是暫時不爛的(de)種(zhong)子(zi)，也不能(neng)順(shun)利(li)完(wan)成發(fa)(fa)芽(ya)過程而夭折。發(fa)(fa)生(sheng)這種(zhong)情況的(de)原因(yin)有(you)以下幾種(zhong)：

浸種(zhong)時間(jian)過短。西瓜種(zhong)子(zi)的(de)種(zhong)皮(pi)是由四層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)不(bu)同(tong)的(de)細胞組織構成的(de)，其中外(wai)(wai)(wai)面的(de)兩層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)分(fen)別是由比較(jiao)厚(hou)的(de)角質(zhi)層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)和木栓層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)構成，吸水(shui)和透(tou)水(shui)性較(jiao)差。如果種(zhong)子(zi)在(zai)水(shui)中浸泡(pao)的(de)時間(jian)短，水(shui)分(fen)便不(bu)能滲透(tou)到內(nei)層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)去。當外(wai)(wai)(wai)層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)吸水(shui)膨脹后，內(nei)層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)仍未吸水(shui)膨脹，這樣外(wai)(wai)(wai)層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)種(zhong)皮(pi)對內(nei)層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)種(zhong)皮(pi)就會產生一種(zhong)張(zhang)(zhang)力。但由于內(nei)外(wai)(wai)(wai)層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)種(zhong)皮(pi)是緊緊地連在(zai)一起的(de)，而(er)且外(wai)(wai)(wai)層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)種(zhong)皮(pi)厚(hou)，內(nei)層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)種(zhong)皮(pi)薄(bo)，所以(yi)內(nei)層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)種(zhong)皮(pi)便在(zai)外(wai)(wai)(wai)層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)種(zhong)皮(pi)的(de)張(zhang)(zhang)力作用下，被迫從發芽孔(kong)的(de)“薄(bo)弱環節(jie)”處裂開(kai)口。

催芽(ya)環境濕度(du)過小(xiao)(xiao)。西瓜種(zhong)(zhong)子經浸泡后，整個(ge)種(zhong)(zhong)皮(pi)(pi)(pi)都會(hui)吸(xi)水(shui)而膨脹。在進行催芽(ya)時，由于(yu)溫度(du)較高，水(shui)分蒸發較快，如果環境濕度(du)過小(xiao)(xiao)，則外層(ceng)種(zhong)(zhong)皮(pi)(pi)(pi)很容(rong)易失水(shui)而收縮，但(dan)因內(nei)(nei)層(ceng)種(zhong)(zhong)皮(pi)(pi)(pi)仍(reng)處于(yu)濕潤而膨脹的(de)狀態。這(zhe)樣一(yi)(yi)來，內(nei)(nei)外層(ceng)種(zhong)(zhong)皮(pi)(pi)(pi)之(zhi)間便產(chan)生了張力差，又因內(nei)(nei)外種(zhong)(zhong)皮(pi)(pi)(pi)是緊(jin)密地(di)連在一(yi)(yi)起的(de)，加之(zhi)內(nei)(nei)層(ceng)種(zhong)(zhong)皮(pi)(pi)(pi)較薄(bo)，所以內(nei)(nei)層(ceng)種(zhong)(zhong)皮(pi)(pi)(pi)便會(hui)在外層(ceng)種(zhong)(zhong)皮(pi)(pi)(pi)收縮力的(de)作用下被迫裂開口(kou)。

催(cui)芽(ya)時(shi)(shi)溫(wen)度(du)過高。西瓜(gua)種(zhong)子催(cui)芽(ya)溫(wen)度(du)一般應維(wei)持在(zai)(zai)25℃～30℃的(de)范(fan)圍(wei)內。如果(guo)催(cui)芽(ya)時(shi)(shi)溫(wen)度(du)超過40℃的(de)時(shi)(shi)間在(zai)(zai)2小(xiao)時(shi)(shi)以上(shang)，就很容易發生種(zhong)皮開(kai)口現象(xiang)。這是(shi)因為(wei)高溫(wen)使西瓜(gua)外層種(zhong)皮失水(shui)而(er)收縮，從而(er)出現與催(cui)芽(ya)時(shi)(shi)濕度(du)過小(xiao)相同的(de)狀況而(er)使種(zhong)子裂開(kai)口。

以上就(jiu)是小(xiao)編帶給(gei)您(nin)的(de)關于避免(mian)西瓜催芽裂口的(de)技(ji)術的(de)介紹，希(xi)望(wang)今天帶給(gei)您(nin)的(de)小(xiao)知(zhi)識(shi)能夠對您(nin)有所幫(bang)助哦。