生活中有很多的人都會喜歡吃玉米，由于玉米的吃法較多，小編也就不一一介紹了。今天主要是想為大家介紹一下玉米種子的四大分類。一般玉米種子會被分為常規種、自交系、單交種、雙交和三交種四種類型。
1.常規種就是植物本身通過自然規律生長出來的種子。
2.自交系種子是在人工控制自花授粉情況下，經若干代，不斷淘汰不良的穗行，選擇農藝性狀較好的單株進行自交，從而獲得農藝性狀較整齊一致、遺傳基礎較單純的系，稱為自交系。連續自交（雌穗和雄穗分別套袋，然后人工授粉）7-8代基本純合成為自交系。自交系種子進行天然或人工隔離進行繁殖可收獲自交系種子。
3.單交種是用兩個自交系雜交生產的雜交種，我們稱之為單交種。可表示為A×B(“×”表示雜交)。單交種的*代具有很強的雜種優勢，表現為抗逆性強、生長健壯、整齊一致，增產幅度大，一般可比天然授粉的農家品種增產20%一30%。可惜的是，當時的玉米自交系其產量性狀較差，生產力太低。
4.還有就是(shi)(shi)雙交(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)和(he)三(san)交(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)。雙交(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)雙雜(za)(za)交(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)的簡稱。由四個(ge)(ge)(ge)品種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)或自(zi)(zi)交(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)系先(xian)兩(liang)(liang)兩(liang)(liang)配成(cheng)(cheng)單(dan)(dan)(dan)交(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)，再由兩(liang)(liang)種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)單(dan)(dan)(dan)交(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)雜(za)(za)交(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)而(er)得(de)的雜(za)(za)交(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)組合。（A×B）F1×（C×D）F1所(suo)得(de)雜(za)(za)種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)即為(wei)雙交(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)。雙交(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)制種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)成(cheng)(cheng)本低(di)，可提(ti)高制種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)田(tian)面積。但需較(jiao)多隔離區，程序(xu)亦較(jiao)復雜(za)(za)，育種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)時間較(jiao)長，增產效果(guo)往往不及單(dan)(dan)(dan)交(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)，在生(sheng)產上的應用(yong)已逐(zhu)漸減少。三(san)交(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)是(shi)(shi)三(san)個(ge)(ge)(ge)血緣不同的玉米自(zi)(zi)交(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)系先(xian)后后經(jing)過(guo)兩(liang)(liang)次雜(za)(za)交(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)而(er)形成(cheng)(cheng)的雜(za)(za)交(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)，可用(yong)(A×B)×C來表示，即以(yi)(yi)A和(he)B雜(za)(za)交(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)獲(huo)得(de)的單(dan)(dan)(dan)交(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)Fl做(zuo)母本再與C自(zi)(zi)交(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)系配成(cheng)(cheng)雜(za)(za)交(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)。三(san)交(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)生(sheng)長的整齊(qi)度和(he)產量不如單(dan)(dan)(dan)交(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)，制種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)程序(xu)較(jiao)單(dan)(dan)(dan)交(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)繁瑣，共需5個(ge)(ge)(ge)隔離區，三(san)個(ge)(ge)(ge)用(yong)來繁殖自(zi)(zi)交(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)系，另有兩(liang)(liang)個(ge)(ge)(ge)分別用(yong)來配制單(dan)(dan)(dan)交(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)和(he)生(sheng)產上用(yong)的三(san)交(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)。由于三(san)交(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)的母本是(shi)(shi)單(dan)(dan)(dan)交(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)，所(suo)以(yi)(yi)制種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)產量高、成(cheng)(cheng)本低(di)。