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Accueil du site → Master → Chine → 2021 → Role of Anatomy and Characteristics of Dispersal and Dormancy/Germination of Canopy Seed Bank in A Desert Annual Species Heteracia Szovitsii

Xinjiang Agricultural University (新疆农业大学) 2021

Role of Anatomy and Characteristics of Dispersal and Dormancy/Germination of Canopy Seed Bank in A Desert Annual Species Heteracia Szovitsii

董文静

Titre : Role of Anatomy and Characteristics of Dispersal and Dormancy/Germination of Canopy Seed Bank in A Desert Annual Species Heteracia Szovitsii

Auteur : 董文静

Grade : Master 2021

Université : Xinjiang Agricultural University (新疆农业大学)

Résumé partiel
Canopy seed bank is a very unique type of seed bank formed by desert annual plants to adapt to the extreme environment of desert.Heteracia szovitsii is an annual plant of the genus Heteracia in the Asteraceae widely distributed in eastern Europe,Central Asia,Iran and Turkey.This species only distributed in the desert or semi-desert in northern Xinjiang in China,which is an important part of the plant community in this region,and has essential ecological significance for maintaining the species diversity and stability of the desert ecosystem.Through field observation,it was found that the stem of this species did not lodge after achene maturation,while the central achene disperse to the soil surface,the peripheral achene and intermediate achene of the inflorescence did not disperse.In this study,the research method of seed physiology and ecology was used to study the anatomical structure of stem and achene base,achene dispersal dynamics,seed dormancy and germination.The main results are as follows :(1)Role of anatomy : compared with Epilasia hemilasia(plants of the Asteraceae having lodging stems ;control),the stem of Heteracia szovitsii was not lodging after the achene matures due to the close to arrangement of vascular bundles,thick phloem fiber,xylem and vessel wall,perimedullary zone and no pith cavity ;The anatomical structure of the abscission zone of polymorphic fruit was obviously different.Among them,the parenchyma cells at the base of the peripheral achene and intermediate achene did not dedifferentiate and did not form abscission layer.While the parenchyma cells at the base of the central achene are dedifferentiated,and the abscission layer is initially formed.

Mots clés : annual ephemeral plant ;seed bank ;fruit polymorphism ;anatomical structure ;physiological dormancy ;

Présentation (CNKI)

Page publiée le 3 mars 2022