و الان دعونا ندرس نبات اخر و هو نبات الاوركيد و ستعرفون السبب حالا
الاوركيد
تصنيف الاوركيد نباتيا :
http://plants.usda.gov/java/Classifi...PO2&display=31
اقتباس
Classification for Kingdom Plantae Down to Subspecies Ipomopsis spicata (Nutt.) V. Grant ssp. orchidacea (Brand) Wilken & R.L. Hartman
Click on names to expand them, and on P for PLANTS profiles
Up to the Kingdom
Kingdom Plantae -- Plants
Subkingdom Tracheobionta -- Vascular plants
Superdivision Spermatophyta -- Seed plants
Division Magnoliophyta -- Flowering plants
Class Magnoliopsida -- Dicotyledons
Subclass Asteridae
Order Solanales
Family Polemoniaceae -- Phlox family
Genus Ipomopsis Michx. -- ipomopsis P
Species Ipomopsis spicata (Nutt.) V.
Grant -- spiked ipomopsis P
Subspecies Ipomopsis spicata (Nutt.) V.
Grant ssp. orchidacea (Brand) Wilken & R.L. Hartman -- orchid ipomopsis P
و هنا تجد العنوان المفاجاءه :
http://fusion.sas.upenn.edu/caterpil...re=23&slide=51
the smallest seeds
DHJanzen100994.jpgاقتباس
An orchid fruit commonly contains millions of seeds, each hardly larger than a grain of sand - hear falling out of a mature orchid fruit. They are wind-dispersed, and are so light that they float about in airspace almost like dust. They must, because once they have fallen below the branches on which they must alight if to survive, they are simply dead. There is very strong selection for aerial bouyancy. But if the seed is so small, how does the seedling get enought nutrients to survive (exposed on a tree branch high in the canopy, it has potentially plenty of sunlight but nutrients are not exactly abundant on a bare tree branch 30 meters above the soil)? Its first tiny roots grow in response to chemicals released by fungi growing on the surface of the tree branch. Fungi have the problem of not being photosynthetic, so they cannot harvest the sunﾒs energy directly. The fungus forms an association with the newly germinating orchid seedling, an association that lasts for life. The fungus collects scarce minerals from the tree bark, debris, animal feces, dust, etc., which it exchanges for sugars being made by the photosynthetic orchid. Orchid breeders have long ago learned this trick, and either germinate their orchid seeds on a mat of the right kind of fungus, or on nutrient-enriched agar, or both (and, in commercial production, generally produce new plants vegetatively from cuttings of established plants rather than grow every plant from seed
ثمرة الاوركيد تحتوى على ملايين البذور و كل منها اكبر قليلا جدا من حبة رمل و تسقط من الثمره الناضجه و هى تتطاير معى الهواء مثل الغبار .
كما ترى ان بذرة الاوركيد مثل الغبار و لكن دعونا نكمل لنتأكد
و تأكيد لا يدع مجال للشك فى الاجابه على السؤال ما هى اصغر البذور على الارض ؟ لنستعرض الموقع التالى :
http://diogenesii.wordpress.com/2007...-in-the-world/
اقتباس
What is the smallest seed in the world?
June 22nd, 2007 • No Comments
HINT: It’s not the mustard seed!
The orchid Gomesa crispa.
The world’s smallest seeds, which have no endosperm and contain underdeveloped embryos, are produced by certain epiphytic orchids (family Orchidaceae) in the tropical rainforest. Some seeds are only 1/300th of an inch (85 micrometers) long, which is below the resolving power of the unaided human eye. One seed weighs only 1/35,000,000th of an ounce (0.81 micrograms). Orchid seeds are dispersed into the air like minute dust particles and come to rest in the upper canopy of rainforest trees, where they eventually germinate.
ترجمه تفسيريه :
ما هى اصغر البذور فى العالم ؟
انها ليست بذور الخردل
بذرة الاوركيد هى اصغر البذور فى العالم وهى لا تحتوى على اندوسبيرم (قشره داخليه ) بداخلها ولكن تحتوى على جنين فى مرحلة تطور ..
وهى من اسرة الاركيدا بالمناطق الاستوائيه البذور طولها 1/300 من البوصه 85 ميكرو ولا ترى بالعين المجرده (ترى تحت الميكروسكوب ) و البذره الواحده وزنها 1/35000 من الاونص ( 0. 81 ميكروجرام ) .
بذور الاوركيد تنتشر فى الهواء مثل الغبار و تستقر تحت الاشجار الاستوائيه حيث تبداء فى النمو .
و سوف اكتفى بالترجمه التفسيريه و بدون تعليق .
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