The task of the plant breeder can be made difficult by any of the following eventualities: the pollen fails to germinate on the stigma, the growth of the pollen tube in the style partially or completely stagnates, no fertilization takes place, the fertilized egg cell does not develop in vivo and aborts, or abscission of the ovaries occurs permanently. If no fertilization takes place after self pollination or cross pollination then it is referred to as self incompatibility or cross incompatibility. In some cases the plant breeder must resort to special procedures to bring about fertilization e.g. by ovule fertilization (here the pollen is artificially brought into contact with the ovules).
圖片編號:
45366903
拍攝者:
7activestudio
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授權類型 | 尺寸 | 像素 | 格式 | 點數 | |
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標準授權 | XS | 480 x 480 | JPG | 13 | |
標準授權 | S | 800 x 800 | JPG | 15 | |
標準授權 | M | 1732 x 1732 | JPG | 18 | |
標準授權 | L | 2236 x 2236 | JPG | 20 | |
標準授權 | XL | 2828 x 2828 | JPG | 22 | |
標準授權 | MAX | 4096 x 4096 | JPG | 23 | |
標準授權 | TIFF | 5793 x 5793 | TIF | 39 | |
進階授權 | WEL | 4096 x 4096 | JPG | 88 | |
進階授權 | PEL | 4096 x 4096 | JPG | 88 | |
進階授權 | UEL | 4096 x 4096 | JPG | 88 |
XS
S
M
L
XL
MAX
TIFF
WEL
PEL
UEL
標準授權 | 480 x 480 px | JPG | 13 點 |
標準授權 | 800 x 800 px | JPG | 15 點 |
標準授權 | 1732 x 1732 px | JPG | 18 點 |
標準授權 | 2236 x 2236 px | JPG | 20 點 |
標準授權 | 2828 x 2828 px | JPG | 22 點 |
標準授權 | 4096 x 4096 px | JPG | 23 點 |
標準授權 | 5793 x 5793 px | TIF | 39 點 |
進階授權 | 4096 x 4096 px | JPG | 88 點 |
進階授權 | 4096 x 4096 px | JPG | 88 點 |
進階授權 | 4096 x 4096 px | JPG | 88 點 |