Pollen vs Nectar
Paj yog ib qho tshwj xeeb tshaj plaws tua tua. Ib lub paj zoo li muaj 4 lub voj voog, ib qho tom qab lwm tus, ntawm ib qho stalk. Lub stalk tuaj yeem luv lossis ntev. Ob qho tib si qis qis tsis cuam tshuam ncaj qha rau kev yug me nyuam. Yog li ntawd, lawv yog hu ua accessory whorls. Upper ob whorls yog ncaj qha mus rau kev yug me nyuam. Yog li ntawd, lawv yog hu ua reproductive whorls. Lub cev xeeb tub yog tsim los ntawm microsporophylls thiab megasporophylls. Microsporophylls hu ua stamens thiab megasporophylls hu ua carpels hauv anthophytes / angiosperms. Qee lub paj muaj ob qho tib si stamens thiab carpels hauv tib lub paj thiab qee cov paj muaj carpels lossis stamens. Thib peb whorl hu ua androecium, uas yog txiv neej whorl. Plaub whorl hu ua gynoecium, uas yog tus poj niam ntawm lub paj. Cov qauv kev ua me nyuam ua rau muaj megaspores thiab microspores lossis paj ntoos. Ib txoj hauv kev tseem ceeb rau disperse microspores los yog paj ntoos yog los ntawm kab. Yuav kom nyiam kab, nectar yog qhov tseem ceeb heev.
Paj noob hlis
Txiv neej spores hu ua microspores. Micro spores tseem hu ua pollen nplej. Nyob rau hauv flowering nroj tsuag, microspores muaj nyob rau hauv lub paj ntoos hnab los yog microsporangium. Microspores yog me me heev, cov txheej txheem feeb. Lawv yuav luag zoo li hmoov av. Txhua microspore muaj ib lub cell thiab ob lub tsho loj. Lub tsho loj tshaj plaws yog lub extine, thiab sab hauv yog lub intine. Extine yog ib txheej tawv, cutinized txheej. Feem ntau nws muaj spinous outgrowths. Qee lub sij hawm nws tuaj yeem ua tau zoo, thiab. Lub intine yog du, thiab nws yog heev nyias. Nws feem ntau yog ua los ntawm cellulose. Lub extine muaj ib lossis ntau qhov chaw nyias uas hu ua cov kab mob pores los ntawm qhov intine loj hlob tawm los ua lub paj paj noob hlis. Lub raj paj ntoos elongates los ntawm cov ntaub so ntswg gynoecium nqa ob tug txiv neej gametes hauv nws. Pollen tube loj hlob thiab nkag mus rau hauv ovule los ntawm micropyle. Tom qab ntawd lub apex ntawm lub paj paj ntoos degrades thiab ob tug txiv neej nuclei raug tso rau hauv lub ovule. Qhov thib ob fertilization tshwm sim los ntawm fusion ntawm ib tug txiv neej nucleus nrog lub qe cell nucleus, muab nce mus rau lub diploid zygote thiab fusion ntawm lwm tus txiv neej nucleus nrog lub diploid secondary nucleus, muab nce mus rau triploid thawj endosperm nucleus.
Nectar
Nectar yog ib qho tseem ceeb tso tawm los ntawm cov qog tshwj xeeb lossis cov kabmob hu ua nectarine ntawm paj. Nectarines muaj nyob rau hauv paj thiab vegetative qhov chaw. Floral nectarine tuaj yeem pom nyob rau hauv ntau txoj haujlwm ntawm lub paj. Nectar secreting ntaub so ntswg ntawm nectar yog pom nyob rau hauv lub epidermis. Secret cells muaj cov cytoplasm tuab heev. Tej zaum lawv yuav yog elongated hlwb zoo li palisade hlwb. Lub nectar yog them nrog ib tug cuticle. Cov ntaub so ntswg muaj kev sib raug zoo nrog nectarine. Qab zib ntawm nectarine yog muab los ntawm phloem. Nectar tuaj yeem raug tawm los ntawm phab ntsa ntawm tes thiab lub cuticle ruptured los yog qee zaum los ntawm stomata.
Pom paj ntoos thiab Nectar txawv li cas?
• pollens yog cov hlwb haploid uas yog cov kua qab zib tsuas yog tso tawm los ntawm cov hlwb.
• pollens koom nrog kev sib deev, tab sis cov kua qab zib tsis koom nrog kev yug me nyuam.
• pollens yog tsim los ntawm microspore niam hlwb, thiab nectar yog zais los ntawm cov ntaub so ntswg secretory nyob rau hauv nectaries.
