Mendelian Segregation in an Interspecific Hybrid Population of Tetraploid X Diploid Coffea Species-Part 1
American Journal of Bioscience and Bioengineering
Volume 1, Issue 5, October 2013, Pages: 55-61
Received: Jul. 25, 2013;
Published: Sep. 20, 2013
Views 3076 Downloads 226
Anil Kumar, Regional Coffee Research Station, Coffee Board, Narsipatnam, Visakhapatnam District, Andhra Pradesh, India
Subbugan Ganesh, Faculty of Agriculture & Animal Husbandry., Gandhigram Rural University, Gandhigram, Dindigul District, Tamil Nadu, India
Follow on us
Mating of two parental varieties always leads to the production of genotypic admixture of both the parental traits in F1 and on selfing the progeny exhibits the phenotypic segregation in a definite proportion in F2. Mendel described it as “Law of Independent Assortment”. It is general belief that coffee varieties do not follow the Mendel’s ratios of segregation. Keeping in view the above findings and beliefs, a study was undertaken during 2008-2011 to observe the segregation pattern in the F2 population of C. arabica cv. ‘Cauvery’ x (C. congensis x C. canephora var. robusta) established at Coffee Research Sub Station, Chettalli, Kodagu District, Karnataka, India in the year 2002. The results of the study revealed that coffee cultivars of commercial importance possessed two types of genetic traits known as dependent and independent characters. The dependent characters showed assortment of characters along with closely related characters and expressed varying degrees of expression. Therefore, the frequency of the occurrence of such phenotypic traits did not considerably match with the expected frequency of the same traits at high probability level and it matched at low probability. The genetic behavior of independent traits exhibited genetic segregation in accordance with the Mendel’s law of independent assortment showing goodness of fit to the dihybrid ratio of 9:3:3:1 with high level of statistical confidence (P≥0.50 up to 0.95). It was observed that the genes regulating the dwarfing effect for coffee bush, thin stem and primary girth, low number of primary branches and reduced length of primary branches were dominant over tall type bush, thick main stem and primary shoot as well as higher number and length of primary shoots.
Genetic Segregation, Variability, Interspecific Hybrids, Dominant Traits, Dihybrid Ratio
To cite this article
Mendelian Segregation in an Interspecific Hybrid Population of Tetraploid X Diploid Coffea Species-Part 1, American Journal of Bioscience and Bioengineering.
Vol. 1, No. 5,
2013, pp. 55-61.
C. S. Srinivasan, A. Kumar, V. S. Amaravenmathy and A. Santaram, "Robusta-like Coffee Plants with Arabica-like Cup Quality- Myth or Possibility,"ASIC,20th International Conference on Coffee Science, Bangalore, October 2004, pp. 787-799
M. S. Sreenivasan, A. Santaram and N. S. Prakash, "Tetraploid inter-specific hybrids in Coffee breeding in India," ASIC, 15thColloque, Montpellier. 1993, pp. 226-233
R. L. Narsimhaswamy and S. Vishveshwara, "Report on hybrids between some diploid species of Coffea L." Indian Coffee, 1961, 25 : pp. 101-111
R. L. Narsimhaswamy and S. Vishveshwara, "Progress report on hybrids between diploid species of Coffea L." Turrialba, 1967, 17 : pp. 11-17
C. C. Chinnappa, "Interspecific hybrids of Coffea canephora and Coffea arabica," Current Sci, 1968, 37: pp. 676–677.
C. A. Krug, In Modern Coffee Production by Haarer, A.E. London, Leonard Hill (Books), Limited, 9 Eden Street, N.W.1, 1956, pp. 495.
C. A. Krug, J. E. T. Mendes, A. Carvalho and A. J. T. Mendes, "A new type of coffee, "Bragantia, 1950,10 (1), pp. 11-25. [In Portuguese, English summary.]
C. A. Krug, and A. J. T. Mendes, "Cytological observations in Coffea – IV," J Genet, 1940, 39, pp. 189–203.