Genetic And Cytological Studies On Oenothera Spp Found In Egypt:

Abd El-migid Ali Abd El-migid

The present investigation was undertaken at the Facultyof Agriculture of Moshtohor (zagazig University Benha Branch)’The objective of this investigation waS concerned with genetic andcytological studies on Q~~21!:!~.!:!! spp found in Egypt COffi’p’8reaonwi th some e x o t i c S ~f l”OITlt.: Germany.’Stu d~te 5 Inc 1u dec’ f0 u r sp eC 1t:: ~ 0 f the ge nus Oc not her a ,-;i.e.jQ. !l.i.~~~~~~ v a r fiedled, Q. ~l~~~~ L. var. grandiflora,Q. ~2~~~i[er!! renner and Q. £~~~~~~ jacy. Karyotype studieswere carried out on these species at the mitotic metaphasestage. All species studied had the same chromosome basic numbcr(x = 7) in the smoatic cell. These chromosomes were metacentric,sub-mctacentric, acrocentric and subacrocentric.The following characters were studi ed1- Earliness. 2- Plant heLg~t3- Number of fruits per plan t 4- ~~I!’bcr of seeds per f r u i t5- Weight of seeds per plant 6- 1000- seeds we i.ghtR-e-s-u-l-t-s---s-h-o-we-d---t-h-a-t--(A): Additive genetic variances were more importantthan dominance in the inheritance of Earlines. Dominancegenetic variances were more important than additive in theinheretance of p la n t height,and numbe r of fruit’! plant fnthe inheritance of weight seed per plant and weight of 100seeds The add i t ive and dom ina n c e t y pes ) 0 f g e n e act ion.were imp 0r tan tin the inher ita nceo f;:the sc .tr a its .(B): The average degree of dominance showed overcomplete dominance whil~partial dominancnumber of f~uit/ pl&nt.showedshoweddominance for plant height Earl i ne ss(C): The negative and positive alleles wereequally distributed among the pare~tal populations for mostof the studied characters.(D): The dominant genes were in excess in the parentsin case of plant height and number of fruit/plant and weightof seed/plant and weight of IOOO-seeds. The valuesof narrow sense heritability in all characters indicatedthat the traits were highly influenced by the geneticfactors. There were positive genotypic correlations betweenearliness and plant height and weight of seed! plant andwe igh tor 1000 seed sand numbe r 0 f f ru it.S I plan 1. There werepositive genotypic correlation between plant height and thenumber of seeds! fruit.Pi rst: Mi totic behaviour: studies included the: IKar, otype and Ka~~)otype analys i s for four parent s 3 •The following description summariz~ the characteristicsof the studied material1- o. nissensis: 2n14. The average total length ofthe hoploid complement in the five cells studiedwas 29.10 + 0.41~. The mean length of the chromosemesranged from 0.95 to 5.84 p. The idiogram showedthat the 6th and 7th chromosomes were subacrocentric.2- Q: biennis: 2n= 14. The average total length of thehaploid complement was 25.45 + 0.12 p. The mean lengthof the chromosomes ranged from 1.25 to 7.06 p. Theidiogram showed that the 3!~ chromosome was acrocenticwith a small satellite attachl~d_ to its short arm.3- o. coronifera: 2n= 14. The average total length of thehaploid complement was 30.22 + 0.06 p. The mean lengthof the chromosomes ranged from 2.06 to The idiogram showed that the 6th chromosome was subacrocentric.4- o. odorata: 2n= 14. The average length of the haploidcomplement was 19.00 + 0.08 p. The mean length of thechr~osomes ranged from 1.51 to 4.49 p. The idiogramshowed that the 5!~, 6th and 7th chromosomes were subacrocentric.Second: Miotic behaviour’ These studies includedthe a b nor rnalit ies 0 f par e n tie san d the hy brid s P r0 ducE: c b ’fd ia Ll e crosses, it. was :not’ic’ed that ther,e are~some c@s~eSo f rin g s • and zig zag e w hie 11 : rnayin d icat e the v reS en ce ’ 0 fc e r t ~ n .Ch r ono sane tr arr s:10 ea tl ons ,In these studies the pollen grain mother cells wereexamined in the stage of metaphase two (diakinases). ~heStudY showed the following: r: l h.1<;:a- ’fhc chromosomes appeared as circles consisting of fourfive or sex chromosomes.b- There were group conststing of two or three or fourfive chromosomes in a zigzag shape.c- There were chromosomes in star shape or a linear shapeor in bivalents.e-There were obend rings of chromosomes.There were br idges chromosomes, and 1_~_gLn_g chromosomesins orne cas e s 0 f par en t e san d h Y b rid s . W nic h mt: ’/ in d i.cat edthePi’G’>~ ;le,~ )f some acrocentricfrom t r.a n s 10 c t ion s •3) POll~n grain viability was highin some hybridsand low in others this strility also,icould be a”t r i bu t e dhet e r 0 z.y’-gou·st 0 c eft a inc h r orno s om a 1 abe r rat ion sin c led i ngtranlocation