根冠

顯微鏡下的根尖。其中1為分生組織、2為平衡細胞（英语：Statocyte）、3為根尖的側面、4為死細胞、5為延長區

根冠（英語：root cap, calyptra）是植物根尖端的數層細胞。根冠的功能包括保護植物根尖的生長點、分泌黏質（英语：Mucilage）以利根部在土壤中的穿透伸展^[1]，並可能參與與土壤微生物的訊息傳遞^[1]，另外根冠中的平衡細胞（英语：Statocyte）與植物感知重力而形成的向地性有關^[2]。

某些寄生植物不具有根冠^[3]^:138。另外許多水生植物(浮萍) 也不具有根冠，而是形成一個稱為根囊（root pocket）的囊狀構造，因其根懸浮於水中，不需穿透土壤，根囊也失去了根冠的保護功能^[4]^:2–76。

參考資料

^ ^1.0 ^1.1 Raven, J.A.; Edwards, D. Roots: evolutionary origins and biogeochemical significance. Journal of Experimental Botany. 2001, 52 (90001): 381–401. PMID 11326045. doi:10.1093/jexbot/52.suppl_1.381.
^ Kuya, Noriyuki; Sato, Seiichi. The relationship between profiles of plagiogravitropism and morphometry of columella cells during the development of lateral roots of Vigna angularis. Advances in Space Research. 2011, 47: 553–562. Bibcode:2011AdSpR..47..553K. doi:10.1016/j.asr.2010.09.009.
^ Jeffrey, Edward Charles. The Anatomy of Woody Plants. Pomeroy, Ohio: Carpenter Press. 2007. ISBN 1-4067-1634-0.
^ Gupta, P.K. Genetics: Classical to Modern. Rastogi Publications. 2007. ISBN 978-8-1713-3896-2.

[Raven2001-1] 1.0 ^1.1 Raven, J.A.; Edwards, D. Roots: evolutionary origins and biogeochemical significance. Journal of Experimental Botany. 2001, 52 (90001): 381–401. PMID 11326045. doi:10.1093/jexbot/52.suppl_1.381.

[2] Kuya, Noriyuki; Sato, Seiichi. The relationship between profiles of plagiogravitropism and morphometry of columella cells during the development of lateral roots of Vigna angularis. Advances in Space Research. 2011, 47: 553–562. Bibcode:2011AdSpR..47..553K. doi:10.1016/j.asr.2010.09.009.

[isbn1-4067-1634-0-3] Jeffrey, Edward Charles. The Anatomy of Woody Plants. Pomeroy, Ohio: Carpenter Press. 2007. ISBN 1-4067-1634-0.

[Guptagene-4] Gupta, P.K. Genetics: Classical to Modern. Rastogi Publications. 2007. ISBN 978-8-1713-3896-2.

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