An experiment was conducted to determine the relationships among the F2 to F6 generations of 9 chickpea crosses (Cicer arietinum L.). The F2 yields had a significant and positive correlation with those of the F3. The mean yields of the F2 and F3 were not associated with the mean seed yield of the F4, F5 and F6. Significant associations among the F2 to F6 were found for days to 50% flowering, days to maturity and individual seed mass. From the results, it is concluded that selection based on early generation bulk yield tests may not be effective. The observed inconsistency in performance of different generations may have been caused by genetic shift and breaking of gene linkage

Geletu, Bejiga

Jagadish, C A

Rheenen, H A van

Singh, Onkar

ICRISAT Open Access Repository

      www.IndianJournals.com            Members Copy, Not for Commercial Sale     Downloaded From IP - 220.225.236.59 on dated 6-Dec-2012•Indian J. Genet., 51 (2): 240-245 (1991)RELATIONSHIPS AMONG THE F2 TO F6 GENERATIONS INCHICKPEA (CICER ARIETINUM L.)GELETU BE]IGA, H. A. VAN RHEENEN,· C. A. ]AGADISH AND ONKAR SINGHInternational Crops Research Institute for the Semi-Arid Tropics (ICRISAT), PatancheruAndhra Pradesh 502324(Received: February 19, 1990; accepted: May 30,1990)ABSTRACTAn experiment was conducted to determine the relationships among the F2 to F,generations of 9 chickpea crosses (Cicer arietinum L.). The F2 yields had a significant andpositive correlation with those of the F3. The mean yields of the F2 and F3 were notassociated with the mean seed yield of the F4, Fs and F,. Significant associations among theF2 to F, were found for days to 50% flowering, days to maturity and individual seed mass.From the results, it is concluded that selection based on early generation bulk yield testsmay not be effective. The observed inconsistency in performance of different generationsmay have been caused by genetic shift and breaking of gene linkages.Key words: Cicerarietinum, generations, correlation, early generation testing, selection, inbredbulks.Chickpea (Cicer arietinum L.) is an important pulse crop and occupies about 10 millioI'.ha worldwide [1]. However, the average yield is only 675 kg/ha. One reason for this couldbe the lack of efficient breeding methods to develop high-yielding and stable cultivars.Progress from selection in a self-pollinated crop depends both on the mean of the inbredbulk derived from a cross, as well as on the variation within this inbred bulk. Theearly-generation multilocational yield-test procedure has been followed for chickpeaimprovement at the ICRlSAT Center [2]. In these tests, F2 populations of the high-yieldingFIS were tested multilocationally, and the best F2S were further tested in F3 multilocationaltrials to reject poorly performing populations in the FI, F2 and F3 generations. Prediction ofthe performance of crosses from early-generation yield testing (F2 and F3) of chickpea wasalso possible [3]. Correlations between the yields of the F2 and F3, F2 and F4, and F3 and F4generations in chickpea were reported to be significant and positive [4]. Significant yieldincrease in chickpea was also realized from early-generation yield tests, compared with both"Addressee for correspondence.      www.IndianJournals.com            Members Copy, Not for Commercial Sale     Downloaded From IP - 220.225.236.59 on dated 6-Dec-2012May, 1991] Correlation among Chickpea Generations 241Table 1. Selected chickpea crosses and their performancein the F3 yield trial of1984visual and random selection [5]. However, poor intergeneration associations were reportedfor pods per plant and grain yield in chickpea [6]. Conflicting results have been reported inother crops. For instance, the F2 yield test results were considered as reliable predictors ofyield potential of different crosses in wheat [7]. Highly significant positive correlations inone season for F2line/F3 mean, F3 line/F4 mean, and F4line/F5 mean yields (r =0.51, 0.68and 0.78, respectively) were obtained in wheat [8]. Similar results were also reported byothers in wheat [9]. However, the use oflater generations only was suggested for yield testsin wheat since it attains a reasonable degree of homozygosity [10]. In cowpea, nonsignificantcorrelations were noted among different generations [11]. Inconsistent associations amonggenerations were found in soybean [12]. The present study has been undertaken, therefore,to investigate the relationships among F2 to F6 generations in nine chickpea crosses, and toarrive at implications for chickpea improvement.MATERIALS AND METHODSThe F3 progenies of 23 crosses were tested in a replicated yield trial at the ICRISATCenter in 1984. Based on the performance, nine crosses representing a wide range in seedyield were selected (Table 1). A part of the F4 seeds was used for generation advance to F5in 1985, while the remaining was kept in cold storage for use as F4 seed in the 1986 planting.The Fl seeds of the nine selected crosses were produced again during the post-rainy seasonof 1985. Fifty three Fl seeds for each cross were sown in pots in the greenhouse to produceF2 seeds. About 120 seeds of F2, together with all the remnant seeds of Fl and 90 seeds of F5per cross, were sown underrainout shelters to generate F2, F3and F6 seeds.Cross Yield Rank StatusThe complete set of F2-F6 (kg/ha) from 25generation bulks of the nine RSG 44 xPhule G-7 2020 1 High yieldercrosses and four control varieties, JG 1265 x2375 1940 4 High yielderAnnigeri, K 850, BDN 9-3, and JG 1265 xPhule G-7 1930 5 High Yielder2375, were grown in 7 x 7 balancedlattice design with 4 replications PhuleG-12x2E 1900 9 Intermediateon vertisol at the ICRISAT Center ICCC 6x2375 1850 11 Intermediatein 1986. The plot size was 4.8 m2, ICCC6xJG315 1840 12 Intermediatewith 4 rows per plot using 30 x 10 2375xJG315 1540 22 Low yieldercm inter- and intrarow spacing. Phule G-12 x64-3 1490 23 Low yielderPresowing irrigation was given 64-3 xBON 9-3 1350 25 Low yielderand two seeds per hole were sown Annigeri (control) 1620 21on October 23, 1986. Weak SE +213seedlings were thinned out 2 CV(%) 21weeks after emergence. The Source: Chickpea Breeding Program, ICRISAT.second irrigation was given 32      www.IndianJournals.com            Members Copy, Not for Commercial Sale     Downloaded From IP - 220.225.236.59 on dated 6-Dec-2012242 Geletu Bejiga et al. [Vol. 51, No.2days after planting. Observations were recorded for days to 50% flowering, maturity andseed yield on plot basis, while observations for other characters were recorded on 5randomly selected plants/plot. The mean of the 5 plants per replication was used for theanalysis of variance. The correlations were determined on the entry mean basis.RESULTS AND DISCUSSIONThere were significant differences among the treatments. Most of the crosses hadsignificantly higher mean yields than the two control varieties, Annigeri and BDN 9·3.However, none of the crosses outyielded the control variety K850 (Table 2). There were nosignificant differences among the mean yields of the crosses in the F2 and F6, whilesignificant differences were obtained among the mean yields of the crosses in the F3, F4 andF5 (Table 2).Significant positive association (r = 0.67) was observed only between the F2 and F3 meanyields (Table 3). Rank switching based on performance was observed for all the crosses indifferent generations, except for RSG 44 x Phule G-7, which had highest mean seed yieldacross generations and consistently ranked first in the F2, F3 and F4. Switching in rank basedon yield between high and medium and medium and low yielding groups were reportedTable 2. Adjusted mean yield (kglha) of the different generations of 9 selected chickpea crosses in 1986Entry F2 F3 F4 Fs F6 Mean F3RankRSG 44 x Phule G-7 2540 (2)· 2610 (1) 2360 (S) 2230 (S) 2430 (5) 2430(2) 1JG 1265 x 2375 2410 (7) 2340 (6) 2070 (11) 2080(11) 2430 (4) 2270(11) 4JG 1265 x Phule G-7 2440 (5) 2550 (3) 2190(10) 2300(6) 2520 (2) 2400(4) 5Phule G-12 x 2 E 2380(S) 2480 (5) 2340(4) 2240 (7) 2300(11) 2350 (6) 9ICCC6x2375 2430 (6) 2270 (10) 2240(S) 2170 (9) 2330(9) 2290 (S) 11ICCC6xJG315 2270(11) 2340(6) 22S0(6) 2080(11) 2460 (3) 2290 (9) lZ2375xJG315 2490 (3) 2520 (4) 2210 (9) 2480 (2) 2380 (7) 2410 (3) 22Phule G-12 x 64-3 2300 (10) 2220 (11) 2350 (3) 2370 (4) 2390(6) 2330(7) 2364-3 x BDN 9-3 2480 (4) 2310 (S) 22S0(6) 2430(3) 2340 (S) 2370(5) 25Controls:Annigeri 2040(13) 2040 (13) 2040(13) 2040(13) 2040(13) 2040 (13)KS50 2590 (1) 2590 (2) 2590 (1) 2590 (1) 2590 (1) 2590 (l)BDN9-3 2140(12) 2140 (12) 2140(11) 2140(12) 2140 (12) 2140(12)2375 2310 (9) 2310 (S) 2310 (5) 2310 (10) 2310 (S) 2310 (S)SE ± = 101.6; F value = 1.7S""; LSD (5%) for 49 entries = 2S7; LSD (5%) for crosses = 129; LSD (5%) forgenerations = 96, and CV = 9%.-Note. Numbers in parentheses show the rank of the crosses.      www.IndianJournals.com            Members Copy, Not for Commercial Sale     Downloaded From IP - 220.225.236.59 on dated 6-Dec-2012May, 1991] Correlation among Chickpea Generations 243earlier [4], but here it was observed even between high and low. For instance, Phule G-12 x64-3 ranked 8th in F2 and 9th in F3, and 2nd in F4 and 3rd in Fs. A similar inconsistency wasreported in soybean [12]. Therefore, although the F2 yield test was effective to predict theperformance of crosses in the F3, as was also reported earlier [2, 3] no reliable predictionscan be made for the yield performance of later generations from the F2 or F3 replicated trialdata.Correlations on entry mean basiswere positive between generations fordays to 50% flowering and days tomaturity, and individual seed weight(Table 4). This consistency may probablyenable the breeder to identify crosseswith the desirable flowering to maturityperiod and individual seed weight.Significant associations among thegenerations were not observed for plantheight, primary and secondary branchesper plant, and pods and seeds per plant.Table 3. Correlations among mean yields of F2 to F6generations of 9 selected chickpea crossesGenerations F2 F3 F4 Fs F6F2 1.00 0.67' -0.07 0.52 0.04F3 1.00 0.04 0.21 0.43F4 1.00 0.09 -0.27Fs 1.00 -0.23F6 ) 1.00'Significant at 0.05 probability level.The observed inconsistency in performance of different generations of chickpea crossesis most interesting and unexpected. The cause cannot be the genotype x environmentinteraction, as the study was conducted in one environment only. Breaking of gencticlinkages might have caused changes in performance, and genetic shifts in the variouspopulations during their production cycles might have added to the inconsistcncy.The results of this study suggest that the performance of the later generations cannotbe predicted because there is an inconsistency in performances of the crosses in differentgenerations. In the present study, no attempt has been made to trace the causes of thisinstability in performance of the crosses. However, if the single-seed descent method hadbeen used to advance the generations of these crosses, the genetic shifts that might haveoccurred in these populations could have been minimised.For practical crop improvement purposes, it might be advisable not to conductearly-generation yield tests among cross bulks, but to select for highly heritable traits witha high correlation over generations.ACKNOWLEDGEMENTSThe senior author is grateful to the International Development Research Centre (lDRC)for the financial support for this stu~y. He is also thankful to the Andhra PradeshAgricultural University and ICRISAT for their assistance and for permitting him to use their      www.IndianJournals.com            Members Copy, Not for Commercial Sale     Downloaded From IP - 220.225.236.59 on dated 6-Dec-2012244 Geletu Bejiga et al. [Vol. 51, No.2Table 4. Correlations for different characters among F2 to F6 generations for 9 selected chickpea crossesCharacter Generation F2 F3 F4 Fs F6Days to 50% flowering F2 1.00 0.70" 0.35" ~.01 0.01F3 1.00 0.55" 0.11 0.41"F4 1.00 0.42" 0.70"Fs 1.00 0.39"F6 1.00Days to maturity F2 1.00 0.65" 0.19 ~.21' 0.17F3 1.00 0.60" 0.38" 0.24'F4 1.00 0.66" 0.23'Fs 1.00 ~.07F6 1.00Plant height F2 1.00 0.01 ~.19 0.13 0.11F3 1.00 ~.04 0.12 0.17F4 1.00 ~.04 ~.~Fs 1.00 ~.OOF6 1.00No. of primary branches F2 1.00 0.20 ~.16 ~.01 0.10F3 1.00 ~.OO ~.04 ~.06F4 1.00 0.05 ~.lSFs 1.00 0.13F6 1.00No. of secondary branches F2 1.00 0.03 ~.09 ~.04 0.12F3 1.00 0.18 0.04 ~.~F4 1.00 0.06 0.04Fs 1.00 ~.16F6 1.00Pods/plant F2 1.00 ~.OS ~.~ 0.16 0.08F3 1.00 0.11 -0.02 0.04F4 1.00 -0.15 ~.OOFs 1.00 0.02F6 1.00Seeds/plant F2 1.00 0.12 0.07 0.16 ~.01F3 1.00 0.11 0.02 ~.OOF4 1.00 ~.12 0.05Fs 1.00 ~.05~~ F6 1.0020-seed wI. F2 1.00 0.41" 0.31" ~.09 0.01F3 1.00 0.27" ~.OS ~.01F4 1.00 0.21' 0.02Fs 1.00 ~.23'F6 1.00Y-ield/plant F2 1.00 ~.07 ~.02 ~.OS 0.07F3 1.00 0.32" ~.01 ~.11F4 1.00 0.05 0.05Fs 1.00 ~.ISF6 1.00'Significant at 5%; "significant at 1%.      www.IndianJournals.com            Members Copy, Not for Commercial Sale     Downloaded From IP - 220.225.236.59 on dated 6-Dec-2012May, 1991] Correlation among Chickpea Generations 245facilities. The help and support of the ICRISAT staff, particularly those from ChickpeaBreeding and Statistics, are gratefully acknowledged.REFERENCES1. FAO. 1985. Production Year Book, vol. 39: 34.2. J. B. Smithson. 1985. Breeding advances in chickpeas at ICRISAT. In: Progress inPlant Breeding (Ed. G. E. Russell). Butterworths, London: 223-237.3. A. K. Auckland and K. B. Singh. 1977. An international approach to chickpea (Cicerarietinum L.) breeding. In: Plant Breeding Papers 2. 3rd Intern. Congr. of SABRAOand Australian Plant Breeding Conference, Canberra, Australia: 8-10, 8-13.4. B. S. Dahiya, 1. S. Solanki and K. Ram. 1983. F2, F3 and F4 bulk yields as indicationsof cross performance. Intern. Chickpea News!., 8: 12-13.5. B. S. Dahiya, R. S. J. Waldia, L. S. Kaushise and 1. S. Solanki. 1984. Early generationyield testing versus visual selection in chickpea (Cicer arietinum L.). Theor. Appl.Genet., 68: 525-529.6. M. A. Rahman and P. N. Bah!. 1986. Evaluation of early generation testing inchickpea. PI. Breed., 97: 82-87.7. G. S. Bhullar, K. S. Gill and A. S. Ahehra. 1977. Performance of bulk populations andeffectiveness of early generation testing in wheat. Indian J. agric. Sci., 47: 330-332.8. B. R. Whan, A. J. Rathjen and R. Knight. 1981. The relation between wheat linesderived from the F2, F3, F4 and Fs generations for grain yield and harvest index.Euphytica, 30: 419-430.9. H. G. Nass. 1979. Selecting superior spring wheat crosses in early generation.Euphytica, 28: 161-167.10. D. R. Knott and J. Kumar. 1975. Comparison of early generation yield testing and asingle seed descent procedure in wheat breeding. Crop Sci., 15: 295-299.11. K Virupakshappa. 1984. Evaluation of single seed descent, bulk and pedigr~emethods in cowpea (Vigna unguiculata L. Walp). Mysore J. Agric. Sci., 18: 76.12. M. G. Weiss, C. R. Weber and R. R. KaHon. 1947. Early generation testiJ:\g in soybean.J. Am. Soc. Agron., 39: 791-811. .

Relationships among the F2 to F6 generations in chickpea (Cicer arietinum L.)

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Relationships among the F2 to F6 generations in chickpea (Cicer arietinum L.)

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