The Influence Of Priming Two Cucumber Cultivar Seeds

More documents

Recommendations

Info

J. Duhok Univ. Vol.13, No.1, (Agri. And Vet. Sciences) Pp 94-102, 2010 49 RESPONSES OF FIVE WATER STRESSED FABABEAN (Vicia faba L.) CULTIVARS TO EXOGENOUS ABSCISIC ACIA APPLICATION * CASER G. ABDEL * and SHAMIL Y. H. M. AL-HAMADANY ** * Dept. of Horticulture, College of Agriculture, University of Duhok, Kurdistan Region- Iraq ** Dept. of Horticulture, College of Agriculture, University of Mosul,- Iraq (Received: May 18, 2010; Accepted for publication: October 23, 2010) ABSTRACT Five fababean cultivars namely Aquadulce, Local Syrian, Taka 357, Twowaytha and Babylon were water-stressed to wilt, and then they were re-watered and immediately sprayed by 0.0, 2x10 -6 M ABA or 2x10 -3 M ABA to evaluate their adaptation to resist drought throughout their responses to varying ABA rates. The results revealed that Aquadulce is the most drought resistance cultivar; this can be ascertained by its prominent yield of dry seeds (33.03 g.plant -1 ), stomata aperture length of upper and lower leaf surfaces (6.7 and 7.1μm, respectively), aperture width of upper and lower leaf surface stomata (1.4 and 1.9μm, respectively). Negligible differences were detected between Aquadulce and Local Syrian cultivars. Moreover, the latter cultivar revealed unequivocal yield of mature pods (91.33 g.plant -1 ). Exogenous ABA application highly improved the drought resistance capabilities of most cultivars, particularly interaction treatment of Aquadulce and 2x10 -3 M ABA, which showed profound dry seeds yield per plant (42.93 g), stomata aperture length of upper and lower leaf surfaces (6.89 and 6.6μm, respectively), stomata aperture width of upper and lower leaf surfaces (1.8 and 2.1μm, respectively). ABA application slightly affected all detected traits. A INTRODUCTION BA is oxidized to phaseic acid (PA), which, in turn, undergoes reduction at the 4'-keto to give dihydrophaseic acid (DPA or epi- DFA). The provision of an -OH group at C-4' allows for conjugation with glucose and the formation of dihydrophaseic acid-glucosides (DPA-GS and epi /-DPA-GS). Abscisic acid glucose ester (ABA-GE), Phaseic acid (PA), Dihydrophaseic acid (DPA), and dihydro phaseic acid-glucosides (DPA-GS) are the major metabolites when ABA is supplied to leaves or other plant parts. They are also the major metabolites when ABA is rapidly synthesized during stress and is dissipated on the release of stress. As to which metabolites predominate varies with species and developmental state (Srivastava, 2002). ABA is synthesized from mevalonic acid in roots and mature leaves, particularly in response to water stress. Stomata under water shortage brings about an increase in ABA which leads to stomata closure and shoot growth inhibitions (Goodwin and Mercer, 1985). In general, application of ABA to plants counteracts the simultaneous applications of IAA, GA, and cytokinin,on the other hand, often * Part of Ph. D. thesis submitted by the second author ABA increases plant responses to ethylene (Srivastava, 2002). Allen et al. (1994) concluded that leaflet grown and measured at high CO2, either water stressed or non-stressed had higher assimilate rate and lower leaf transpiration rate and therefore higher water use efficiency than those grown and measured at ambient CO2 levels, as stressed progressed water use efficiency decreased about 30 to 50% with respect to unstressed treatments. Increases in leaf temperature and gradient in leaf to air vapour, as water stress progressed were similar for both levels of CO2 treatment. Franks and Farquhar (2001) observed that ABA-treated plants had significantly smaller stomata and higher stomata density in their lower epidermis. Stomata aperture versus guard cell pressure (Pg) characteristics measured with a cell pressure probe showed that although the form of the relationship was similar in control and ABAtreated plants, stomata of ABA-treated plants exhibited more complete closure at Pg = 0 MPa and less than half the aperture of stomata in control plants at any given Pg. Scaling from stomata aperture versus Pg to stomata conductance versus Pg showed that plants grown under ABA treatment would have had significantly lower maximum stomata conductance and would have operated with lower stomata conductance for any given guard
J. Duhok Univ. Vol.13, No.1, (Agri. And Vet. Sciences) Pp 94-102, 2010 cell turgour. This is consistent with the observation of lower mesophyll CO2/air CO2 in ABA-treated plants with an air CO2 of 350 µmol.mol -1 . It is proposed that the ABAinduced changes in stomata mechanics and stomata conductance versus cell pressure (Pg) characteristics constitute an improvement in water-use efficiency that may be invoked under prolonged water stress conditions. Therefore, an attempt was conducted to evaluate the drought resistance of five fababean cultivars and through their responses to drought and ABA application. MATERIALS AND METHODS This experiment was carried out during 2003 – 2004 growing season at Danadan Research Field, University of Mosul. The objective of this was to evaluate the responses of five water stressed fababean (Vicia faba L.) cultivars to varying abscisic acid (ABA) application rates, in terms of improving adaptation and water stress resistance. Therefore, fababean seeds were obtained from Atomic Energy Organization, Baghdad, in 2002. Factorial in Randomized Complete Block Design (F-RCBD) was used in this trail. Factor A was represented by five fababean cultivars namely Aquadulce (a1), Syrian (a2), Taka357 (a3), Twowaytha (a4) and Babylon (a5). Factor B was represented by exogenous ABA application rates, where 0.0 M ABA (b1), 2x10 -6 M ABA (b2) and 2x10 -3 M ABA (b3). Subsequently 15 treatment combinations were included in this experiment. Each treatment was replicated three times, and every replicate was represented by three pots of 20 cm in diameter and 30 cm depth. Pots were filled with silty loam soil (14.3% clay, silt 56.3%, sand 29.4%, bulk density 1.5g.cm -3 , field capacity 0.2, and wilting point 0.11). Pots were covered by clear polyethylene at a height of 1.5 m to keep plants away from rainfall incidences and to facilitate bumble bees visiting during flowering stage. Five seeds were sown in every pot, on November 5 th 2004 under. Two weeks later, plants were thinned to leave three plants per pots. Pots were irrigated whenever 50% of the plants were wilted throughout the growing season in each treatment. Two doses of NPK (27:27:0) each at rate of 2.5 g per pot, the first was on December 20 th 2003 and the second was on February 10 th 2004. Two protective sprays were made by 1g.l -1 benomyl fungicide. Plants were sprayed twice by either distilled water, 2x10 -6 M ABA or 2x10 -3 M ABA on February 20 th 2004 and were repeated once more whenever plants were rewatered after wilting. Finally, plants were harvested on April 28 th 2004. Plant height, internodes length, and pod length were measured. Branch number, leaflet number, node number, flowering node number, flower number per inflorescence, first fruiting node, number of fruiting nodes, pod number, seed number per pod, aborted seeds per pod, and aborted ovules per pod were counted. Leaf area and leaf area index were calculated (Abdel, 1994). Fresh plants, matured pods, dried pods, dry pod integuments, dry plants, and dried seeds were weighed. Light microscope of 40x objective and graded 7x lenses were used to count epidermal cells population, stomata population and stomata dimensions. RESUTS AND DISCUSSION Substantial differences between responses of Aquadulce and Syrian cultivars to varying ABA concentrations were not observed in all detected vegetative parameters. Moreover, these two cultivars profoundly exceeded Taka 357 in plant height (42.2 and 36.5%, respectively); node number (58.6 and 58.3%, respectively), leaflet number per plant 54.8 and 48.7%, respectively), and plant dry weight (40.9 and 30.9%, respectively). Aquadulce cultivar was also superior over Twowaytha and Babylon cultivars in leaflet number per plant, leaf area index and plant dry weight. Taka 357 gave the lowest growth, however, it manifested apparently higher individual leaflet area (19.04 cm -2 ) and internodes length (5.5 cm), as compared to all other cultivars (table, 1). The obtained results revealed that the vegetative growth of indeterminate Aquadulce cultivar was very close to that which have been obtained from previous investigation (Abdel, 1997), which may suggested drought resistance capability. Previous studies revealed that growth of indeterminate cultivars namely, Tiger, Newblackfly and Blaze revealed higher drought resistance abilities as compared to indeterminate Beryl (Abdel, 1982). They apparently exceeded Taka357, Twowaytha, and Babylon under rainfalls. Aquadulce growth was substantially improved under rainfalls and supplementary 49
Page 1 and 2:
J. Duhok Univ. Vol.13, No.1, (Agri.
Page 3 and 4:
Page 5 and 6:
Page 7 and 8:
Page 9 and 10:
Cultiva tion metho ds and cvs (A*B)
Page 11 and 12:
Indirect cultivation Cultivation me
Page 13 and 14:
Dir ect cul tiv ati on J. Duhok Uni
Page 15 and 16:
Cultivation methods and cvs (A*B) J
Page 17 and 18:
Page 19 and 20:
Page 21 and 22:
Page 23 and 24:
Page 25 and 26:
Page 27 and 28:
Page 29 and 30:
Page 31 and 32:
25% water 50% water media ×p J. Du
Page 33 and 34:
25% water 50% water media ×p J. Du
Page 35 and 36:
Page 37 and 38:
Page 39 and 40:
Page 41 and 42:
Page 43 and 44:
Page 45 and 46: J. Duhok Univ. Vol.13, No.1, (Agri.
Page 79 and 80: 44 Hybrids 2 A 2 D 2 E 2 H 2 h a
Page 95: J. Duhok Univ. Vol.13, No.1, (Agri.
Page 109 and 110: 601 Inreed line 1 59.00 ef 2 63.66
Page 135 and 136: 133 Table (1):- Effect of Humic aci
Page 137 and 138: 135 Humic acid (g.L -1 ) 0.0 1 2 Me
Page 147 and 148:
Page 149 and 150:
Page 151 and 152:
Page 153 and 154:
Page 155 and 156:
Page 157 and 158:
Page 159 and 160:
Page 161 and 162:
Page 163 and 164:
Page 165 and 166:
Page 167 and 168:
Page 169 and 170:
Page 171 and 172:
Page 173 and 174:
Page 175 and 176:
Page 177:
show all

The Influence Of Priming Two Cucumber Cultivar Seeds

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?