Effect of Selection on Amylose and Amylopectin Concentration in Maize (&lt;i&gt;Zea mays&lt;/i&gt; L.)

Iu Obi,Gc Onyishi

doi:10.4314/as.v10i3.8

Abstract

Two cycles of reciprocal recurrent selection at the University of Nigeria, Nsukka shifted the average percentage amylopectin of the eight populations of maize (Zea mays L.) from 74.50 to 81.30 per cent, 74.00 to 82.00 percent , 77.50 to 82.50 percent, 76.00 to 82.00 percent, 77.00 to 82.5 per cent, 74.50 to 82.05 per cent, 75.50 to 82.30 per cent and from 77.00 to 82.32 percent. Selection was not effective in developing high amylose strain. The average percentage amylose of the eight populations of maize decreased from 25.50 to 20.00 percent, 26.00 to 19.30 percent,22.50 to 20.00 percent, 24.00 to 20.10 percent, 23.00 to 19.31 percent, 25.50 to 19.40 percent, 24.50 to 20.41 percent, and 23.00 to 19.23 percent. The developed synthetics can be used as commercial varieties per se, as reservoirs of germplasm for further improvement, and for the extraction of superior inbred lines for use in hybrid maize production.Key words: Reciprocal Recurrent Selection, Amylopectin, Amylose, Maize synthetics, Germplasm

Highlights

Maize grain is primarily carbohydrate but contains small proportions of protein, oil and some minerals
Breading for improved amylose and amylopectin is possible but achievable judging from various reports such as that of Betty (2011); Onyishi and Obi (1991) who reported an encouraging progress in breeding for improved amylose and amylopectin; and Obi and Onyishi (1994) who reported significant improvement in protein content of maize from two cycle of reciprocal recurrent selection and observed that dominant gene action is very important in breading for chemical constituents
The materials used in the study involved four open-pollinated early maturing varieties,DMR-ESR-Y,EV-8431-SR-BC4,DMRESR-W,IK(1)-8149-SR-BC2 designated as A1, A2,A3,A4, respectively and open-pollinated late maturing varieties, DMR-LSR-Y, West-YellowM2, TZB-SR, DMR-LSR-W designated as B1, B2, B3, B4, obtained from the International Institute for Tropical Agriculture (IITA) Ibadan, Nigeria

Summary

Introduction

Maize grain is primarily carbohydrate but contains small proportions of protein, oil and some minerals. Normal maize carbohydrate consists of about 20.0 – 30.0 per cent amylose and 70 – 80 per cent amylopectin. Waxy starch or amylopectin of maize has different commercial uses.

Results

Conclusion