Composition of kernel-amylose and -resistant starch among subtropically adapted maize

Abstract

High amylose starch has many benefits to human health besides diverse industrial applications. Traditional maize grains possess <35% amylose and <5% resistant starch. Here, 48 subtropically adapted maize inbreds were evaluated at three locations for various starch attributes. Wide genetic variation for total starch (66.8–74.1%), amylose (1.7–66.2%) and resistant starch (1.4–39.4%) was observed. Minor influence (<5% of total variation) of environment and genotype × environment interactions was observed across the traits. PMI-AML-146 and PMI-AML-147 possessed high amylose (66.2% and 64.2%) and resistant starch (39.4% and 38.0%). At the same time, PMI-WX1 and PMI-WX3 possessed low amylose (1.7% and 3.6%) and resistant starch (1.4% and 1.7%). Amylose was positively correlated with resistant starch (RS, r=0.81) except in a few inbreds. Though CML373 possessed comparatively higher amylose (47.7%), it had a low RS (16.8%). On the contrary, PMI-AML-150 had lower amylose (25.5%) but higher RS (21.4%), suggesting that besides amylose, other factors also play a role in constituting RS. The high amylose and RS inbreds identified here would serve as donors in the breeding programme. This is the first report on genetic variation in amylose and resistant starch in subtropically adapted maize.