Diallel analysis of ear moisture loss rate, SPAD chlorophyll, and harvest index in maize with the leafy (Lfy) gene

• Published in: Journal of new seeds Vol. 7; no. 2; pp. 1 - 16
• Main Authors: Kang, M.S, Board, J.E, Aminha, N, Zhang, Y, Moreno, O.J, Balzarini, M.G
• Format: Journal Article
• Language: English
• Published: Taylor & Francis 01.04.2005
• Subjects: chlorophyll; corn; corn ears; corn stover; diallel analysis; dry matter accumulation; ear moisture loss rate; general combining ability; genotype; genotype-environment interaction; grain crops; grain weight; grain yield; harvest index; leafy gene; Maize (Zea mays L.); seed weight; SPAD chlorophyll; specific combining ability; water content; Zea mays
• ISSN: 1522-886X; 1522-9025
• DOI: 10.1300/J153v07n02_01

Maize (Zea mays L.) containing the leafy (Lfy) gene has not been extensively used in genetic investigations because the gene has been patented. The objective of this study was to obtain genetic information on ear moisture loss rate (EMLR), leaf number above the ear, SPAD chlorophyll of leaves, and harvest index via use of a diallel cross (Griffing's Method 3) of seven leafy parents. Ear moisture loss rate was measured via an electronic probe device (EMLR-P) and the "oven method" (EMLR-O). General combining ability (GCA) was significant for EMLR-P and EMLR-O, but GCA × year interaction existed only for EMLR-O. Thus, multiple-year data are needed for investigations of EMLR-O, which increases evaluation cost. Additive genetic correlation between EMLR-P and EMLR-O was 0.96. Parents Mo17 and 914 had the desirable, negative GCA effects. The number of leaves above the ear was a complex, quantitatively inherited trait, as revealed by significant GCA, specific combining ability (SCA), nonmaternal (reciprocal), and SCA-by-years interaction effects. The cross Mo17 × 914 showed positive SCA effect and parental line B73 showed positive GCA effect for leaf number. For SPAD chlorophyll, GCA and SCA were significant, as were GCA × year and SCA × year interactions. Parents Mo17 and Hy had positive GCA effects and A619 had a negative GCA effect for SPAD chlorophyll. The cross A619 × 914 had undesirable negative SCA effect for SPAD chlorophyll. Harvest index (HI), stover, grain weight, and total dry matter (TDM) had significant GCA and reciprocal effects. To increase HI, B73 and 914 should be desirable parents. Parent Hy possessed favorable GCA and maternal factors to increase stover and TDM. A regression equation for grain weight (GWT) was: GWT = -643.0 + 0.28 TDM linear + 2221.3 HI linear (R 2 = 90%), suggesting that grain weight can be improved by increasing TDM and HI in the leafy maize used here.