根冠

根冠（英语：root cap, calyptra）是植物根尖端的数层细胞。根冠的功能包括保护植物根尖的生长点、分泌黏质（英语：Mucilage）以利根部在土壤中的穿透伸展^[1]，并可能参与与土壤微生物的讯息传递^[1]，另外根冠中的平衡细胞（英语：Statocyte）与植物感知重力而形成的向地性有关^[2]。

显微镜下的根尖。其中1为分生组织、2为平衡细胞（英语：Statocyte）、3为根尖的侧面、4为死细胞、5为延长区

某些寄生植物不具有根冠^[3]^:138。另外许多水生植物(浮萍) 也不具有根冠，而是形成一个称为根囊（root pocket）的囊状构造，因其根悬浮于水中，不需穿透土壤，根囊也失去了根冠的保护功能^[4]^:2–76。

参考资料

^ ^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.

[1]

[2]

[3]

[4]