Pinus Botany Note

PINUS 113 Systematic position: Class Coniferropsida Oredere coniferteles Family-pinaceae CGenus-pinus Morphology: (1) pinus is a large evere green tree. The sporcophytic plant body gives a typical pyramidal appearance. (2) The plant body is differentiated in to reout vem 2 Leaves The preimarey root is typicou teprout. The roots eute covered with fungeu mycorichiza fungou hyphae called (3) The Fungi present in the ectotropic mycorrhiza. απέ Boletus clavaercio of clan basidiomycetes They remain in symbiotic association with the που . (4) The Hem of pinus is cylindrical erect, woody & branched & the breanches cute monopodial. 15)2 types of branches are developed in pinus like branches of unlimited growth on long mout & breanches of limited growth on dware shoot. (6) The Leaves are dimorepnic Like scare leaf & middle line folliage leaves. Reproduction: (1) The main piant body of pinces is sporophyte 2 reproduce by sexual method. (2)94 produces microsportes & megarpones micrcosporangia & megasporcangia developed on micco sporophy & megasporophyll respectively which are agreigated togethere in to mourrond femoue cone. ketrectively. 114 (3) The pinus is monopelous & the male cone 2. femoue cone are formed of different branches Of the same plant. Moue cone: 37 (1) The more cone occurs in clusteres neare the ends of Leaves. Long branches in the anxi'l of scare (2) Each mave cone has 60-200, spirally arranged microporophyus (3) The microsporrophyns cercises from the central anis. 2 has 2 microsporangia on its uppere sureface. (4) The terminou expanded Mercile paret of тісногрокорнул is known us Apophysis. (5) Even micrcosporangium lum is eusporcangiate in development & contecins large no. of microspore mother cell. (6) Each micro sporre mothere cell divides melotically to forem u haploid microsportes ore pollen grains. Development of male gamete; The mtecco sporres & pollen grains have 3 layered wall like the outer cuticularised erine, the middle Layers forums 2 bouton balloon maped wings & the innere most delicate intine. (2) The micropores is a uninucleate stre. & the germination Harets while Ierosporangium. they are inside (3) Afterc du development Parchu the pollen grains reaches the pollen chambers of the ovule (4) 1st the micro-worce divides by 2 treansverese !!! division producing & prothallial cell & one antheridian cell (5) Then the anthercidioce call divide to forem a generative cell 2 a e tube cell. Larege (6)gn this ucelled condition the pollen greains Released from the microsporangium by wind. Female cone (1) The femoue cone has a centreal arts to which the mega porophy's are attached (2) on the suppere surface of oviles are attached. mega porcophylls 2 each mego (3) Ecien mega sporcophyas has. 2 lange outer bract scare, ovule Ferrous scare. ovule & fe move gametophyte (1) The ovule is surereanded by a single integument With a micropile directed towards the cints of the cone. (2) The integuments suretteunde the Nucellus ( mega sporrangtum). (3) The nucellus contains a single mega sporre muthere. cell which undergo riedue Hun division forming 4 haploid megawortes (4) The 3 megaspores forwards the mi degenerate remains. 2 only one choplliere & function eat megaspore megaspore egasporre anderigo. (5) The megaspore whten is followed by free nuclear division cell wall formation producin ve a female gametophyte with 2 ore 3 arechegonia at the micrco pillar end. (6) The arcchegonium contains the egg. Pollination & post pollination change: The 4 celled Pollen greatns or micro spores are released. From the male cone a di's percued by wind. (2) By coind pollination the pollen greain reaches, the female cone 2 comes in direct contact with the apex of nucellus (3) The pollen tube produced in microspores containing tube cell & genereative cell (1) (4) The generative Walk cell. cell divides into body cell & (5) The tube cel degenerate with in pollen teube. (6) The body cell divides to forcm 2 male gametes or sperm. Fertilization: (1) of takes place aftere a yeare of pollination. (2) one of the male gamete foreming a zygote. fuses with the post Fertilization changes :: (1) The zygote is the firest cell of sporcophytic nod phases. (2) The zygote underrgp free nucleare division producing nuclei which moved, towards the lowe're end of zygote. 3) The wall formation Harts foreming of cells u fiery & in each tiers 4 nuchel present. (4) This Ar-is couled proembreyo. (5) The embryo open ther tier. differrentiates into utieres like cosette tiere suspensere fierei apicas (6) The 1st 2 tiers have no function & degenerate, (7) The cens of suspenser tier elongate forming 197109, Suspensor (8) Eccen cell of capicay tiere produced an embryo 2 Al Producing Cin embryoncu Here. But after sometime one 23 degenerate. Embreyo only elongate (10) The suspensore fiere foreces the embriyo towards endo perem. (11) Endo sperem differentiates into hypocorctile with a no. of cotyledons & apicortile. (12) The embryo & then by is surrounded a seed coat. by ein endo vperem (13) on germination of seed the embryo produces a seedling which develop in to a pine treee. (14) poly embryonic is common is pinus. (15) Additional embryo originated by simple polyembryony from multiple zygote.