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Accueil du site → Doctorat → Allemagne → 2008 → Pollination of medicinal plants (Nigella sativa and Coriandrum sativum) and cucurbita pepo in Jordan

Rheinischen Friedrich- Wilhelms-Universitat Zu Bonn (2008)

Pollination of medicinal plants (Nigella sativa and Coriandrum sativum) and cucurbita pepo in Jordan

Abu-Hammour, Khaled

Titre : Pollination of medicinal plants (Nigella sativa and Coriandrum sativum) and cucurbita pepo in Jordan >

Auteur : Abu-Hammour, Khaled

Université de soutenance : Rheinischen Friedrich- Wilhelms-Universitat Zu Bonn

Grade : Doktor der Agrawissenschaften (Dr.agr.) Doktor-Ingenieur 2008

The aim of this doctorate thesis was to reveal the reproductive system and to identify the main pollinators in Jordan of Black Cumin (Nigella sativa) Coriander (Coriandrumer sativum) and squash (Cucurbita pepo). These plants are wide spread in Jordan and are used for medical treatments and as spices and food. Furthermore two surveys of solitary bees and the mellitophilous flowering plants were conducted in the Jordan Valley at 150 m below and in Northern Jordan at 200m above sea level from January until April. On these transects 261 bee individuals out of 11 Genera were recorded. The density of bees in the Jordan Valley was higher than in the northern study site. Most bees were active during March. 106 species out of 23 families of melittophilous plants were found. Most species were from the families Caryophyllaceae, Gramineae and Compositae. The following pollination treatments were conducted. 1. Open pollination (flower is accessible for all visitors) ; 2. Spontaneous selfing (bagged flower, no pollinator can touch the flower, but selfing can happen) ; 3. Forced selfing (emasculation and hand pollination, afterwards bagged) ; and 4. Cross pollination. Measured and compared were the seed set after these trials. They were repeated in two years at the two study sites in order to see whether different pollinators are present. Nigella sativa : Black cumin produced most seed after open pollination (86% of the ovaries set seed), when the flowers were forced to self pollination seed set reached at 85%, after cross pollination seed set was 75%, seed set in emasculated flowers (selfing) rendered only 13%. Nigella has a special way to assure spontaneous self pollination. This mechanism was described and compared with a similar mechanism in Nigella arvensis. The only pollinators were honey bees. Coriander sativum : Coriander has hermaphroditic male and female flowers. The hermaphroditic flowers are strictly self-incompatible. However geitonogamie between male and hermaphroditic flowers renders at least 25%. Analyses of fertilized seeds showed that they contain 14,9% Protein while non fertilized ones had a significant lower content of 4.7%. This again shows that pollination does not only produce well shaped fruits but also increases the quality of the content of seeds. Only honeybees pollinated the Coriander flowers. Cucurbita pepo : Open pollination gave the best results (88%) while hand cross pollination was less effective (86.1%). Geitonogamy reached similar results as Hand cross-pollination with 84%. In these flowers only honeybees were recorded.


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Page publiée le 16 octobre 2008, mise à jour le 30 décembre 2018