無籽西瓜種辨真偽。無籽西瓜是目前大麵積種植的主要西瓜品種類型，它是四倍體西瓜與二倍體西瓜（普通有籽西瓜）的(de)雜(za)交(jiao)種(zhong)，即(ji)三(san)倍(bei)體(ti)西(xi)瓜(gua)。生(sheng)產(chan)上(shang)常(chang)采(cai)用(yong)對(dui)四(si)倍(bei)體(ti)西(xi)瓜(gua)自(zi)然(ran)隔(ge)離(li)法(fa)人(ren)工(gong)去(qu)雄(xiong)生(sheng)產(chan)三(san)倍(bei)體(ti)西(xi)瓜(gua)種(zhong)子(zi)。少(shao)數(shu)情(qing)況(kuang)下(xia)由(you)於(yu)製(zhi)種(zhong)過(guo)程(cheng)中(zhong)四(si)倍(bei)體(ti)西(xi)瓜(gua)去(qu)雄(xiong)不(bu)徹(che)底(di)，故(gu)出(chu)現(xian)無(wu)籽(zi)西(xi)瓜(gua)種(zhong)（三倍體西瓜種）zhonghunzayoushaoliangdesibeitixigua，jijiawuzixiguazhong，yincibixubasibeitixiguazhongcongwuzixiguazhongzhongqingchuchuqu。ruguoqingchubuchedi，wuzixiguazhongzhongrengkenenghunzayousibeitixiguazhong。gebieqingkuangxiayourenguyibasibeitihuoerbeitixiguazhonghunzazaiwuzixiguazhongzizhongmouli。nongminpengyouyingzhuyiduisanleixiguazhongzitezhengjinxingbianbie。wuzixiguazhongzi（三倍體種子）種(zhong)胚(pei)不(bu)充(chong)實(shi)
，種(zhong)殼(ke)表(biao)麵(mian)常(chang)凹(ao)陷(xian)不(bu)平(ping)，種(zhong)臍(qi)部(bu)珠(zhu)眼(yan)突(tu)起(qi)，種(zhong)殼(ke)上(shang)有(you)較(jiao)深(shen)的(de)木(mu)栓(shuan)質(zhi)縱(zong)裂(lie)，種(zhong)子(zi)明(ming)顯(xian)比(bi)二(er)倍(bei)體(ti)西(xi)瓜(gua)大(da)。四(si)倍(bei)體(ti)西(xi)瓜(gua)種(zhong)子(zi)種(zhong)胚(pei)充(chong)實(shi)，種(zhong)子(zi)圓(yuan)壯(zhuang)，這(zhe)是(shi)與(yu)無(wu)籽(zi)西(xi)瓜(gua)種(zhong)的(de)明(ming)顯(xian)區(qu)別(bie)。另(ling)外(wai)，四(si)倍(bei)體(ti)西(xi)瓜(gua)種(zhong)種(zhong)殼(ke)表(biao)麵(mian)常(chang)突(tu)起(qi)，種(zhong)殼(ke)上(shang)一(yi)般(ban)有(you)木(mu)栓(shuan)質(zhi)縱(zong)裂(lie)
，種(zhong)臍(qi)部(bu)珠(zhu)眼(yan)突(tu)起(qi)。二(er)倍(bei)體(ti)西(xi)瓜(gua)種(zhong)種(zhong)粒(li)明(ming)顯(xian)小(xiao)於(yu)無(wu)籽(zi)西(xi)瓜(gua)種(zhong)和(he)四(si)倍(bei)體(ti)西(xi)瓜(gua)種(zhong)
，種(zhong)臍(qi)部(bu)珠(zhu)眼(yan)不(bu)突(tu)起(qi)，臍(qi)部(bu)較(jiao)窄(zhai)
，種(zhong)殼(ke)上(shang)無(wu)縱(zong)裂(lie)。

 

　　棉花種健籽與非健籽的鑒別。棉花健籽發芽率高，生活力強，播種後有利於全苗
；非健籽發芽率、出(chu)苗(miao)率(lv)低(di)
，難(nan)以(yi)一(yi)播(bo)全(quan)苗(miao)。生(sheng)產(chan)中(zhong)要(yao)注(zhu)意(yi)選(xuan)用(yong)健(jian)籽(zi)，淘(tao)汰(tai)非(fei)健(jian)籽(zi)。鑒(jian)別(bie)兩(liang)種(zhong)棉(mian)籽(zi)可(ke)從(cong)淨(jing)種(zhong)子(zi)中(zhong)隨(sui)機(ji)抽(chou)出(chu)少(shao)量(liang)種(zhong)子(zi)，用(yong)剪(jian)刀(dao)一(yi)一(yi)剪(jian)開(kai)
，根(gen)據(ju)色(se)澤(ze)、飽滿程度進行鑒別。色澤新鮮
、油點明顯
、種仁飽滿者為健籽；色澤淺褐、深褐
、油點不明顯
、種仁癟細者為非健籽。也可采用開水燙種法：從淨種子中抽取少量棉花種子
，如50粒或100粒。將種子置於小杯中，用開水浸燙，並攪拌5分鍾。待棉籽短絨浸濕後

，取出放在白瓷盤中，根據顏色差別進行鑒別。呈深褐色或深紅色的為成熟籽；呈淺褐色、淺紅色或黃白色的為不成熟籽。如果非健籽（不成熟籽）較多
，則不能作種。