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Abstract - 150 - SUMMARY This research was carried out at the Experimental Station of Fuculty of Agriculture, Moshtohor, Benha Branch, Zagazig University in two successive seasons (1989/1990 and 1990/199’,). The aim of this investigation was to study the effect of three growth regulators namely gibberelliC , germination (percentage and rate), morphological characters, paclobutrazol (PAC) and. ethre1 (CEPA) on acid chloroplast pigments, flowering, anatomical features and carbohydrat.e and protein fraction contents. Also the NPl levels were detected. Three cultivers of leguminous plants were used in thi s stud Y one fenugreek cul tivar (Balad f ) and two pea eva. (Perfection and Little Marvel). The three growth regulators and their concentrations were as fo110ws:- 1- Gibberellic acid (GA3) .••.••• one and 10 ppm. 2- Paclobutrazo1 (PAC) •••••.. 10 and 100 ppm. 3- Ethrel ICEPA) ..•••••• 50 and 500 ppm. These growth regula tors were used as soaking ma ter ia1 in the liboratory (for germination and growth chamber) or as spray on the yegetatiye system of the plants of each cul tiyar. Spraying took place twice at the age of 30 and L.5 daY’. after saving in the green-house. The experiaenl~8 were carried out in the following systea:- --_.---_.------- - - - -- ----~-----_.----~~--~~~ - 151 - 1- An experiment to detect the effect of these growth regulators or. the germination process (percentage and rate) in the Lab or e. tory under controlled cond i tions. 2- An exper iment in order co detect the effect of these growth regulators on the chloroplast pigments and morphological characters. the organic contents of the the vegetative system (carbohydrates in the seedling stage. Water and protein fractions) culture was used in the laboratory under controlled conditions. 3- Experimunt s aimed to study the effect of these growth regulators on the morphological characters, chloroplast pigments. flowering. anatomical characters and dry weight of plant HganS and the nutrients content (i.e. NPK) of roots and leaves of the three cultivars under study in the two seasons. This took place under the green-house conditions. Three experiments were carried out in each growing sHasons each concern one of the three evs. under study. The obtairled results could be sua.arized 8S followa:- 1- Ger.talltioa: As for the effect of GA] on germinatiOn of fenugreek seeds (Baladi ;ey.), no response ~xisted with regard to gerllinat i on pe~c:.entage or rate vi th the low concentration (one pplll). ’ft- higher c~ncelltr8tion - (10 ppa) increased the percl~ntage of germ1nation but decreased its rate. --- - -- --- ------------------- -- - - - - _.- - ._. - .- - .- - 152 - FollowiHg up the effect of GA3 on the two pea c va , (Perfection and Little Karval) shoved increase in the percentage ,.f gerDinated seeds accompanied vUh reduction in its rate. low concentl~ation (one ppm) did not show any clear effect on the germtnation process. The oa1y exception that existed was that the For the effect of PAC on germination of fenugreek seeds (Baladi cv.) it was noticed that the low concentration (10 ppm) . did not affect the germination percentage while the higher concentration (100 ppm) , significan<~lY decreased this percentage. However those twO concentrations increased the rate of germination. As for the effect of GA3 on the twO pea cvs. the response ’ias different from that of fenugreek as here the twO assigned concentrations nearly resembled the control. For the effect of CEPA on germination of fenugreek seeds thl! two concentrations (50 & 500 ppm) significantly decreasec: the aeraination percentage while the rate of gerainat:.on vas increased. The effect of eEP! OB the pea cys. it vas generaly noticed that -t its tVO co.centrations decreased the geraination percentage and increased its rate. _. _. - -------------_.----_._. --”-- --,-~-- ---’- -_._-- - - -- ---- - - - - - ---- - 153 - 11- Morphological characters: A- In the growth chamber: 1- Effect )f gibberellic acid. With rE~gard to fen u g r e e I:. (Baladi cv.) the tWO concentrations of GA3 (1 s of tap root but increased in ternodes a nd lea f area. ill ppm) (lccreascd the length tho stem length, length of The increase showed a linear relationshiP with the used concentrations. With the twO pea cvs. GA 3 concentrations showed different effects. With the Perfection cv. the twO concentrations decreased t 1e length of the tap c v , did no’: exhibit any effect root, while Little Marvel in this respect. But the st em leng tt. inc rea sed with the two c oncen tra tions 0 f GA 3 in the twO pea cultivars. However the number of the internodes was not affected. internode ,tas increased. Meanwhile the mean length of the 2- Effect of paclobutrazol: In f,!nugreek the length of the tap root was not affected by the loW concentration (10 ppm) while the higher concentration increased itS length. But these twO concentrations decreased the length of stem. Number of internodes and leaf number were not affected. However the leaf area was decreased. The twO •• _ CYS. affected with PAC. showed clear reduction in t-’ -tap root length. the atea length. number of inten.odes •• ean length of internode ~ nuaber of leaves and leaf area. - -- - -,----~-~-------_.---’-’ - - ,-- ~---- -’- --- --- - - - _. - _.- ~ - 154 - 3- Effect of ethre1: Its effec.t on fenugreek and the two pea cvs. resembled to a certain extent PAC for tap root length or stem length or number of internodes. mean length of internode. number of leaves and leaf area. B- In the green-house experiaent: Data wa! recorded in two growth periods (45 and 60 days from sc,wing) in the green-house, i.e. 15 days after the first and the second spray. The obtained results of the two seasops (1989/90 and 1990/91) were nea~ly the same. Also, the effect increased with the increase of the applied concentration of any of used growth regulator. 1- Effect of giberellic acid: As for fenugreek GA 3 as a whole decreased the length of the tap root and increased the number of the developed branches, r.umber of leaves and leaf area. However”, vi th the hilher concentration (10 ppa) the nu.ber of the internodes was not affected with the first spray but increased 1ft th the second spray. The two seasons showed some differences with regard to total number of branches. The t”o pea e.•s. (Perfection and Little Harvel) behaved differentl, to .~ extent. ,- For Perfection. for instance, the low cl)ncent”t10n of GA3 (ODe ppa) decreased the tap root len.·:h aorft.an vi th the higher cODc.atration (10 ---------- ------ - 155 - ppm). But in Little Marvel the same effect existed with the low con:entration while the higher concentration increased r h i n length. of branches while it increased the stem length. number GA 3 did not stimulate the formation of leaves and leaf area. 2- Effect of paclobutrazol: In fenugreek. this growth regulator caused increase in the length of tap root. number of branches and leaves. However. it decreased the stem length and length of stem and internodes. their number and mean length of the internode, r.umber of leaves and leaf area. This indicate the stunting effect of this growth regulator. As f01” the two pea CYS. the twO concentrations increased the root length and decreased the stem length in the two growth periods through the two seasons for the two cultiurs (Perfection and Little Marvel). The effect was more clear with the higher concentration. The application of PAC decreased many traits such as length of internodes and lea far ea ’b u t inc reased number of lea Y e s , The PAC e nha nc e d branching in the second growth period. This stimulating effect was different in the twO seasons. 3- Effect of ethrel: ..J£~ With fenuBteek the tvo concentrations (SO and 500 exhibited’ifferent responses with regard to length ppm) ~ .--- - -- _. -- - - _.- -_. -_.- - _. - .- - - _.--- ----- --- - _.-- ~-- _.-- - 156 - of tap root as the low concentration increased its length while the higher one led, to its reduction. The two concentrations reduced’ the stem length, number of leaves and leaf area. Of inter rest was that the two concentrations increased thiu number of branches in the two seasons. In peas (Perfection and Little Marvel) the two concentration of this growth regulator decreased the length of both tap root and stem in the two growth periods. Generally, t!lese concentrations caused reduction in many of the morp~ological characters as length of internode, number of IE aves. ALs o , a promoti ng effect in branchi ng existed. Tt.e increase was more than any other growth regulator USE!d in the present study. The eff eet of any of these growth regulators (GA3• PAC and CEPA) nearl y shove d the same trend wi th any of the three cultivars under study. 111- Chlorplaat pi••• ata: A- ~r~hrth eb•• lter .s.perl.eat: Both ft:nugreelt and peas exhibited different responses. With fenu~reek, all the assigned concentrations of GA 3 (1 and 10 p•• ) or CEPA (50 and 500 pp.) decreased chlorophyll a • band carotenoids in leaTes. Hove.,er the application of PlC with its concentrations (10 and 100 ppm) increased th4se pia_ents. --- -- --~-~------ - - - -- _.,-- ----- - 157 - For pea cv. Perfection. all the three growth regulators used led in general to reduction in chlorophyll a. band carotenoids except with the low concentrations of GA3 increased chlorophyll b. With pea c v , Little Marvel. chlorophyll a increased by the applic!tion of any of the three growth regulators except with the higler concentration of ethrel (500 ppm) that showed small reduction. Also. chlorophyll b increased except with GA 3 and PAC where small reduction existed. B- Green··house experi-ent: Here. the results differs from those obtained in the growth chamber. It was noticed that GA.3 and CEPA with their assigned concentrations caused reduction in the contents 0 E the leaves of fenugreek and peas in the two growing puriods (45 and 60 days after sowing). PAC exhibited u reverse effect. IY- Floweria.: 1- Thl! number of flowers as well as the date of the existance of the first flower under the green-house conditionH were recorded. For fenugreek t GA 3 wioth the higher concentrat ion (10 pp.) led to co •• iderable earliness in flowering (the first flover e::isted36 days before the control). The PAC (100 --------------------- ---- ---------_.-- _. ------- ------- - -- -- - - 158 - ppm) caused but a little delay in this existance. But CEPA caused a clear delay. Generally, the low concentrations of these growth regulators exhibited but little earliness in the existance of the first flower. For the two pea cvs. this date was not affected with the growth re·gulators treatment except that of CEPA which exhibited some delay especially with its higher concentration. 2- Number of flowers: The app lication of GA 3 or PAC as a whole led to some increases in this number/plant. But CEPA (50 ppm) enhanced flower formation. however, the two, concentrations of CEPA caused reduction in the number of flower per plant. v- Anato.ieal studiea: The study included the internal structure of the stem and leaves (f fenulreek and pea plants. A- Anatony of tbe aain stea: In fenugreek. tbe application of GA3 generally reduced the stea d:.a.eter but the PAC increased it. the increase or decrease that esisted vaB due to reduction in the thickness cf aany different ti••••• (the epiderais, cortex, The hiaher concentration of PAC (100 pp.) incre~ed the nuaber of Y8scular bundles but - _.- - -_. - - -- .- _ .. _- -- - - --- - -- - - - - - - - - - - ---- --- - - _. - -- ----- ~ ..- - -- ------- - ---_.--_.----_ ..- ----- - ._ .. - - 159 - CEPA greatly reduced most of the characters under study. Of interrest was the great reduction in the number of vascular bundles. existed with the concentration of 500 ppm. differences. caused reduction in same effects that with some little many traits (stem pith and dimensions PAC exhibited the As existed for :he two pea cultivars, fenugreek were noticed the but in thickness, c1)rtex, pericyelic fibers, of vascular bundle, phloem ••••etc). same effectB that were noticed in the two p e e evs. (Perfection and for instance fenugreek. However, Little Marvel) showed some diffel ences., the low concentration increased t~e number of the small vascular bundles but thiS number was not affected in Little Marvel. However, the higher concentration of PAC increased the number of vascular bU:ldles. But CEPA the twO concentrations existed different e::fects. The low concentration (50 ppm) increased the stem d i.ameter and stem-wall thickness but the higher one (500 ppm) reduced them. Generally the two concentratiOns increased most of the anatomical characters. The number of the large bundles were always siailar to that the control. B- Anat)m, of the leaf: The s tudy i_eluded the internal structure 0 f the leaf at the position tf the midrib. -’- --_ .. _-~---~--_._-------- -- --- - - - - - - - - - - - - - -- - -- .-- ._- _.- _.- -- ------- ._- -- -- -- - - --- _.- -----_. ------_. - _._ ..- ~-- - - - - - - - - - -- - - - - - --- - -- - - 160 - For fenugreek, the higher concentration of GA3 (10 ppm) caused reduction in the thickness of the midrib and blade. This vas due to reduction in the thickness of many tissues such as epidermis (upper and lover), the palisade fi ber zone tissue and spongy and ph loem. The tissue. co11enchyma tissue. dimensions of the vascular bundle increased. nJmber of vessels and their width. the thickness of both midrib nnd blade. PAC increased This increase was due to the tissues. 1’:s increase of epidermis, palisade and spongy concentrations showed different effects for instance tte lov concentration (10 ppm) increased the dimensions of the bundle. xylem thickness and number of vessels v:lile the higher concentration caused reduction I\s for CEI)/\ the tva concentrations in these cr aracters. concen:ration leaf s r r uc r u r e . While the 50 ppm of the Leaf (midrib and lamina), ’)00 p p rn ’ 1\ C r c ;1 sed t his t hie k ne s s • differently affected the decreased the thickness the of With the tva pea cultiva~ 3, the effect was nearly the same. however some dif[erell(”{~S existed. For instance. in the Perfection cv. some characters did not show any deviation from the control with the application of GA3 as number of palisade or spongy layers. Even though, the lower concentration (one ppm) caused reduction in the width of the va sc u La r bundle and the higher one (10 ppm) caused an increo!e in this trait. -~-- -- -- - ---_. - _._--~-------- - 162 - of the higher concentration (100 ppm). CEPA with its two concentrations (SO and 500 ppm) caused reduction 1n the dry weight. ’~he most level of reduction was at the flowering period with the higher, concentration (75% less than the control). With the two pea cultivars (Perfection and Little Harvel). the application of any of these growth regulators (GA), PAC and CEPA) showed different effects with regard to dry weiglLt. For instance, in Perfection c v , this weight was reduced by the application of GA3, while PAC caused increase in the dry wei gh t , CEPA caused 8 li t t Ie increase in the veg,;,tat i ve peri od of growth and red uc t ion at the flowering p er Lo d , As a whole GA3 increased the dry weight in Little lIIarvel cultivar. PAC caused increase in this weight at 1:heveget a ti ve period and dec r e a s e at flowering period. CE,PA led to increase of the dry weight at the two growth ~eriods (Vegetative, flowering). VII- Che.ica1 ana1yeie: A- Growth cha.ber experi.ent: 1- Protein fractions: It was noticed that all the applied concentration of the three growth regulators (GA3, PAC and CEPA) increased the total soluble protein fractions in the shoots of f e nug r e.sk (Baladi cy.) and pea (Perfection cy.). These increments were .ainly due to the increase of albumins ---- ._.-_ .. --_. - .- - ----~-_._-_.-_ ... - 163 - and glutelins. Of interest was that in the Little Marvel cv. the assigned growth regulators reduced the total soluble protein fractions. This reduction was mainly due to reduction in albumins. 2- Totar carbohydrates: Wi th fenugreek plant the low concentration (one ppm) of GA3 was nearly as that of the control while the higher cocentration (10 ppm) increased the carbohydrate contents. PAC with its t.wo concentrations (10 and 100 ppm) reduced the total caro ohyd rat ee , CEPA with its low concentration (50 ppm) led to increase the total carbohydrates in the shoots while the higher concentration decreased this content. As for the pea cultivars (Perfection and Little Marvel) all the growth regulators used (GA3, PAC and CEPA) increased the carbohydrate contents in ~he shoots of the seeding. This increase were more obvious in the Perfection cv. B- Tile Brees-honee eIpert.ent: The NPl content was esti.ated in roots and leaTes of the treated plants 8S well as the control. The level of these ele.ellts was increased with the application of these gro”th rea-dators in the roots and leaves of fenugreek (Baladi c v ,) aad also the two pea evs. (Perfection and Little Harvel) at the two growing periods (45 and 60 days --- -~-_.. - -- - - ----- ---- ------- - 164 - after sowing). Besides~ some of the assigned concent~ations showed different effects with regard to the levels of NPK (Tables 27 and 28) • |