Genetic variability for yield and quality characteristics in South African cotton germplasm (Gossypium hirsutum L.)
| dc.contributor.advisor | Van Deventer, C. S. | |
| dc.contributor.author | Emeetai-Areke, Thomas Edison | |
| dc.date.accessioned | 2017-06-26T07:49:15Z | |
| dc.date.available | 2017-06-26T07:49:15Z | |
| dc.date.issued | 1999 | |
| dc.description.abstract | English: The objective of this research was to study the genetic variability in South African cotton germplasm and to identify superior parental lines for the improvement of yield and quality characteristics. 2 Six parental lines (Irco, Palala, OR27, 2131-2-5, DPAc90 and Sicala) were crossed in diallel fashion. The parents and their F1-offspring were planted in four experiments at two locations, Rustenburg and Loskop, in two successive years, 1997/1998 and 1998/1999. Twenty agronomic and yield characteristics were measured. The data for each characteristic were subjected to a diallel analysis, using the computer program "Agrobase". 3 Significant mean differences were found among the parental lines and their F1-offspring for most of the characteristics measured at both locations, during the two successive years. The only exceptions were SI and LB. On average, Palala and Sicala proved to be the best yielders at Rustenburg, while Irco yielded the best at Loskop. Sicala proved to be the best for FL in both environments, while OR27 was on average the best for FS at both Rustenburg and Loskop. Palala was the best for FU at Loskop, while bath Irco and 2131-2-5 ranked the best at Rustenburg. For the character MC, all the parents were within the acceptable range of 3.5 - 4.5. 4 OR27 proved to be the best combiner for yield and most of the yield components, at both Rustenburg and Loskop. The parental line Sicala proved to be the best general combiner for fibre length, while OR27 was the best general combiner for fibre strength and fibre uniformity at both locations. Parental lines DPAc90 and Irco were the best general combiners for MC at Rustenburg and Loskop respectively. 5 The G.C.A.:S.C.A. ratios were close to unity for most of the characteristics, including yield. Some of the characteristics, such as HC (31.6 - 46.8), GOT2 (1.7 - 17.3), FS (4.6 - 15.7) and FL (2.9 - 14.4) had relatively high G.C.A.:S.C.A. ratios. 6 Extremely high broad sense heritabilities were found for HC (0.92 - 0.98), FL (0.92 - 0.95) and GOT2 (0.77 - 0.93). Extremely high narrow sense heritability was found for HC (0.88 - 0.92), and relatively high values were also computed for FL (0.32 - 0.77), GOT2 (0.42 - 0.87), and FS (0.48 - 0.63). 7 Extremely high significant genetic correlations were computed between SCYP and LYP (0.97), SCYPLT and LYP (0.97), SCYPLT and LYPLT (0.98), SCYP and HC (0.98), LYP and HC (0.97), SCYP and TBF (0.96), SI and U (0.98) and FL and FS (0.97). 8 Relatively high positive correlated response was found between SCYPL Tand GOT2, U, LB, TBF and UHB in bath trials at Rustenburg. In the trials planted at Loskop characteristics like SCYP, SCYPL T, LYP and HC, had relatively high, positive correlated response with most of the other characteristics. High negative correlated response was found between SCYP and GOT, BS, HC and FL in the Loskop trials, while LYP had a negative response with GOT and BS. 9 Mid-parent as well as high or best parent heterosis were highly positive for SCYP and LYP, in most of the crosses. The cross Sicalaxlrco, showed on average the highest amount of heterosis at Rustenburg and Loskop during 1997/98 season. The amount of heterosis for SCYPL Tand LYPL T varies from large negative to large positive values. | en_ZA |
| dc.description.abstract | Afrikaans: Die doel van die navorsing is om die genetiese variabiliteit in die Suid-Afrikaanse katoen kiemplasma te bestudeer en om meerderwaardige ouerlyne vir die verbetering van opbrengs en kwaliteit te identifiseer. 2 Ses ouerlyne (Ireo, Palala, OR27, 2131-2-5, DPAe90 en Sieala) is op dialIele wyse gekruis. Die ouers en hul F1-nageslagte is op twee lokaliteite, Rustenburg en Loskop, in twee opeenvolgende jare 1997/98 en 1998/99 aangeplant. Twintig agronomiese en kwaliteits-eienskappe is gemeet. Die data van elke eienskap is op dialIele wyse met behulp van die "Agrobase" rekenaarprogram geanaliseer. 3 Betekenisvolle gemiddelde verskille is tussen die ouerlyne sowel as hul F1-nageslagte gevind vir meeste van die gemete eienskappe, op beide lokaliteite, gedurende die twee opeenvolgende jare. Die enigste uitsonderings was SI en LB. Gemiddeld het Palala en Sieala die hoogste opbrengste by Rustenburg gehad, terwyllreo die hoogste opbrengs by Loskop toon. Sieala was die beste ouer vir FL in beide omgewings, terwyl OR27 gemiddeld die beste ouer was vir FS op Rustenburg en Loskop. Palala was die beste ouer vir FU by Loskop, terwyllreo en 2131-2-5 die hoogste waardes vir FU toon op Rustenburg. Vir die eienskap MV val al die ouers binne die aanvaarbare grense van tussen 3.5 en 4.5. 4 OR27 is die beste kombineerder vir opbrengs en meeste van die opbrengskomponente by Rustenburg sowel as Loskop. Die ouerlyn Sieala is die beste algemene kombineerder vir vesellengte terwyl OR27 die beste kombineerder is vir veselsterkte en veseluniformiteit by beide lokaliteite. Ouerlyne DPAc90 is die beste kombineerder vir MC by Rustenburg en Loskop, onderskeidelik. 5 Die G.C.A.: S.C.A verhoudings is baie na aan een vir meeste eienskappe insluitend opbrengs. Sekere van die eienskappe soos HC (31.6 - 46.8), GOT2 (12.7 - 17.3), FS (4.6 - 15.7) en FL (2.9 - 14.4) het relatief hoë G.C.A.:S.C.A verhoudings. 6 Uitermate hoë breë-sin oorerflikhede is verkry vir HC (0.92 - 0.98), FL (0.92 - 0.95) en GOT2 (0.77 - 0.93). Uitermate hoë nou-sin oorerflikheid is verkry vir HC (0.88 - 0.92). Relatief hoë nou-sin oorerflikhede is bereken vir FL (0.32 - 0.77), GOT (0.42 - 0.87) en FS (0.48 - 0.63). 7 Uitermate hoë genetiese korrelasie koëffisiente is bereken tussen SCYP en LYP (0.97), SCYPL T en LYP (0.97), SCYPL T en LYPL T (0.98), SCYP en HC (0.98), LYP en HC (0.97), SCYP en TBF (0.96), SI en LI (90.98) en FL en FS (0.97). 8 Relatief hoë gekorreleerde responsies is verkry tussen SCYPL T en GOT2, LI, LB, TBF en UHB, in beide proewe by Rustenburg. In die proewe wat op Loskop geplant is, toon die eienskappe SCYP, SCYPLT, LYP en HC relatiewe hoë positiewe responsies met meeste van die ander eienskappe. Hoë negatiewe gekorreleerde responsies is waargeneem tussen SCYP en GOT, SB, HC en FL, terwyl LYP ook 'n hoë negatiewe responsie met GOT en SB toon. 9 Middel-ouer sowel as beste ouer heterose is hoog positief vir SCYP en LYP in meeste van die kruisings. Die kruis Sicalaxlrco toon gemiddeld die grootste hoeveelheid heterose by Rustenburg gedurende 1997/98. Die hoeveelheid heterose vir SCYPL Tand LYPL T varieer van hoog negatief tot hoog positief. | af |
| dc.description.sponsorship | National Agricultural Research Organisation - Uganda | en_ZA |
| dc.identifier.uri | http://hdl.handle.net/11660/6403 | |
| dc.language.iso | en | en_ZA |
| dc.publisher | University of the Free State | en_ZA |
| dc.rights.holder | University of the Free State | en_ZA |
| dc.subject | Genetic variability | en_ZA |
| dc.subject | Yield | en_ZA |
| dc.subject | Fibre | en_ZA |
| dc.subject | Quality | en_ZA |
| dc.subject | Cotton | en_ZA |
| dc.subject | Cotton -- Breeding -- South Africa | en_ZA |
| dc.subject | Thesis (Ph.D. (Plant Breeding))--University of the Free State, 1999 | en_ZA |
| dc.title | Genetic variability for yield and quality characteristics in South African cotton germplasm (Gossypium hirsutum L.) | en_ZA |
| dc.type | Thesis | en_ZA |