Stay green criterion in maize breeding programs

Abstract

Genetic variation for stay green character has been exploited in maize improvement mainly in the light of selecting high yielding rather then typical stay green genotypes. Stay green is an indicator of good plant health later in the season, reduced progressive senescence, tolerance to post-flowering drought and stalk lodging what ensure superiority of stay green genotypes in comparison to non stay green ones, especially in drought conditions. The objective of the study was to examine relationship of stay green and grain yield with some vegetative characters in two genetically broad based maize populations. Correlation as well as path coefficient analysis have been used. The most consistent correlations with stay green were established for leaf and stalk water content, which has been confirmed by path-coefficient analysis. At the same time correlation and path coefficient analysis showed quite opposite results about relationship between stay green and grain yield. While correlation coefficients between these two traits were weak and insignificant (r=-0.095), path coefficient analysis showed very strong and highly significant direct effect of stay green on grain yield (p=0.834**).

Genetička varijabilnost za stay green je u oplemenjivanju kukuruza više korišćena u svetlu selekcionisanja visoko prinosnih nego tipičnih stay green genotipova. Stay green je indikator dobrog zdravstvenog stanja biljke u kasnijim fazama vegetacije, redukovanog progresivnog starenja, tolerantnosti prema stresnim uslovima izazvanim sušom i tolerantnosti prema poleganju biljaka, što obezbeđuje superiornost stay green genotipova u odnosu na one koji ne poseduju ovo svojstvo (non stay green). Cilj istraživanja bio je da se utvrde međusobni odnosi stay green-a i prinosa zrna sa nekoliko vegetativnih svojstava u dve sintetičke populacije kukuruza šire genetičke osnove. Najkonzistentnije korelacije sa stay green-om ustanovljene su za udeo vode u listu i stablu, što je potvrđeno path koeficijent analizom. Najniža genetička korelacija sa prinosom zrna ustanovljena je za stay green (r=-0.095), dok je path koeficijent analizom utvđen vrlo jak i visoko signifikantan direktan uticaj stay green-a na prinos zrna (p=0.834**).