A FORMULA TO PREDICT INBREEDING DEPRESSION IN F2 POPULATION OF MAIZE

J. Al-Khafajy, Mustafa; M. Elsahookie, Medhat; H. Cheyed, Saddam

	A FORMULA TO PREDICT INBREEDING DEPRESSION IN F2 POPULATION OF MAIZE
The Iraqi Journal of Agricultural Science
Article 1, Volume 43, Issue 1, 2013, Pages 1-9
Authors
Mustafa J. Al-Khafajy; Medhat M. Elsahookie; Saddam H. Cheyed
Abstract
A field experiment was conducted on the form of the Dept. of Field Crop Sci. / College of Agriculture / University of Baghdad in spring and fall seasons of 2009 and 2010 . Ten inbreds of maize were planted and crossed to each other to produce single crosses . In the second season, single crosses were planted along with thin parent to produce three – way and double crosses . In the third seasons panet and crosses were planted . Crosses were selfed to produce F2 seeds and increase seeds of inbreds . In the fourth season, all grin types were planted , and their agronomic traits were evaluated . Values of P of inbreds , F1 and F2 were calculated for agronomic traits . The new formula to predict inbreeding depression ( ID ) F2 plant without growing them relied on : relative constant ( χ ) , P and F1 of traits . It was set up as : ID % = [ ( 1 – χ ) – χP / F1 ] × 100 . The inbreeding depression obtained was compared to that reported by Ouapadissakoon and Wernswam . The to values were just fit for all traits tested ; plant grain yield , kernel weight , kernel / ear , rows / ear , leaf area / plant , and plant total dry matter . However ,the F2 populations used were of three – way and double crosses . the F2 of single crosses if used ,the formula will stand right . This formula is very useful to predict inbreeding depression without the need to grow F2 seeds . whereas , other three formulas were set up to predict means of agronomic traits for inbreds ( parents ) ( P ) , F1 and F2 means P = [ ( 1 – χ ) – ( ID % ) ] × F1 / χ , for predicting : F1 = χP / ( 1 – χ ) – ID% , and for predicting values of F2 = ( 1 – ID % ) F1 . Results show very high fit for all traits estimated . Hence, we recommend using these formulas to predict any value mean of any trait of P , F1 , and F2 populations .

Statistics Article View: 44 PDF Download: 16