Potencial de genótipos de trigo duro para produtividade e caracteres agronômicos no Estado de São Paulo

Abstract

RESUMOO trigo duro produz a semolina que, extraída dos grãos, é a matéria-prima empregada na elaboração de macarrão. Assim, o objetivo deste estudo foi avaliar o potencial produtivo e comportamento agronômico de 17 linhagens de trigo duro (BH-1146 , altura das plantas, comprimento da espiga e comprimento do internódio da raque (cm), número de grãos por espiga e massa de cem grãos (g). A tolerância à toxicidade de alumínio foi realizada empregando soluções nutritivas, no laboratório. As cultivares IAC-1001 e IAC-1003 destacaram-se quanto à produção de grãos nos dois locais. As linhagens 2, 9 e 13 possuem porte semianão mais baixo; as linhagens 4, 15 e a cultivar IAC-1001 exibiram espigas mais compridas; as cultivares IAC-1001 e IAC-1002 sobressaíram-se pelo grande número de grãos por espiga; a 'IAC-1003' pelos grãos mais pesados e as linhagens 1, 4, 15 e 17 revelaram maior comprimento do internódio da raque. Houve tendência dos genótipos de porte semianão mais alto serem mais produtivos, com maior número de grãos por espiga e grãos mais pesados. As linhagens obtidas pelo programa de melhoramento do IAC foram tolerantes à toxicidade de alumínio e as cultivares-controle sensíveis.Palavras-chave: triticum durum L., melhoramento de plantas, tolerância ao alumínio. ABSTRACT POTENTIAL OF DURUM WHEAT GENOTYPES FOR PRODUCTIVITY AND AGRONOMIC TRAITS IN SÃO PAULO STATESemolina extracted from grains of durum wheat is used for manufacturing pastas. Therefore, it is of interest to evaluate the yield potential and agronomic behavior of seventeen durum wheat inbred lines (BH-1146/ LGN//2*IAC-1003) originated from Instituto Agronômico (IAC) breeding program and three check cultivars IAC-1001, IAC-1002 and IAC-1003, introduced from International Maize and Wheat Improvement Center (CIMMYT), Mexico. The experiments were carried out in upland conditions at Capão Bonito and under irrigation at Mococa, in 2007 and 2008. The following characters were evaluated: yield (kg ha -1 ), plant height, head length and raquis internode length (cm), number of grains per spike and 100 grains weight (g). The tolerance to aluminum toxicity was evaluated in nutrient solution, under laboratory conditions. 'IAC-1001' and 'IAC-1003' showed good performance in relation to grain yield at the two locations. The inbred lines 2, 9 and 13 showed shorter semi dwarf plant type; inbred lines 4, 15 and the cultivar IAC-1001 had longer heads; 'IAC-1001' and 'IAC-1002' exhibited more fertile spikes; 'IAC-1003' heavier grains and the inbred lines 1, 4, 15 and 17 presented higher raquis internode length. The more productive genotypes tent to present taller semi dwarf plant types, more of grain per spike and heavier grains. The inbred lines from the IAC breeding program were tolerant to aluminum toxicity and the check cultivars were sensitive.

Selection gain and interrelations between agronomic traits in wheat F5 genotypes

“…Spike size is an important agronomic trait for breeding, especially as it is positively associated with grain yield. Results from a previous study have shown that a larger spike resulted in a greater number of spikelets (Silva et al, 2010).…”

Correlation and selection gains in F6 wheat genotypes

“…Table 3: Estimates of phenotypic (r p ), genotypic (r g ) and environmental (r e ) correlation between agronomic traits, for days of emergence to flowering (DF), plant height (PH), spike length (SL), number of tillers (NT), number of spikelets (NS), kernel weight (KW), thousand kernel weight (TK) for wheat genotypes Spike length showed a significant negative genotypic association with thousand kernel weight (-0.442), indicating that larger spikes tend to increase yield. In this way, these traits are important to be considered in the cereals breeding, due to being closely related to the yield components and define wheat productivity (Silva et al, 2010).…”

Path analysis between yield components of wheat under different top-dressing nitrogen management

“…Thus, the increase in the length of the spike and the mass of grains in the main spike tends to increase the yield of wheat grains. Silva (2009) considers that the spike length is a trait of interest for genetic improvement, as it is closely related to the components that define grain yield in wheat culture.…”