Cold tolerance of inbred lines and sister line crosses of maize with different genetic backgrounds

Abstract

An improvement in the early spring cold tolerance of maize would allow it to be grown in more northern areas with a cooler climate, while on traditional maize-growing areas the profitability of maize production could be improved by earlier sowing, leading to a reduction in transportation and drying costs. The cold tolerance of crosses between inbred lines and sister line crosses belonging to three related groups that combine well with each other (BSSS, Iodent, Lancaster) was tested in the Martonvásár phytotron. The results confirmed those of earlier experiments and led to the following new conclusions: - the average emergence time of the tested Iodent inbred lines was longer than that of the BSSS and Lancaster groups, - all three groups contained inbred lines with significantly earlier emergence than the others, - the average emergence percentage and individual shoot dry matter production in the Iodent group were also lower than in the other two groups, - a close negative correlation (r = -0.70) was found between the number of days to emergence and the individual dry shoot mass. The results were used to select inbred lines and sister line crosses with various genetic backgrounds that could be used in crosses aimed at improving the resistance of hybrids to cold stress in early spring.