TITLE:
Genetic Variability of Brachiaria ruziziensis Clones to Collaria oleosa (Hemiptera: Miridae) Based on Leaf Injuries
AUTHORS:
Daniela Maria da Silva, Jair Campos de Moraes, Alexander Machado Auad, Marcy das Graças Fonseca, Fausto Souza Sobrinho
KEYWORDS:
Signal Grass; Bug; Damage Score; Chlorophyll Content
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.4 No.12,
December
26,
2013
ABSTRACT: Collaria oleosa causes leaf injuries to the main forage grasses used for cattle feeding in Brazil. The aim of this work was to determine resistance of B. ruziziensis clones against C. oleosa. Eighty B. ruziziensis clones were maintained in greenhouse, in which C. oleosa natural infestations have been occurring in previous years. After 40 days, damage score and chlorophyll content reduction were assessed for all clones. By using these parameters, genetic gain was estimated based on REML/BLUP mixed models. We observed significant differences for damage scores and chlorophyll content reduction among B. ruziziensis clones, evidencing genetic variability in this forage specie in regard to resistance against C. oleosa. Gain derived from selection of the 10 best clones was 18.2% and 5.80% when considering the damage score and chlorophyll content reduction, respectively. The clones CNPGL BR 10, CNPGL BR 64, CNPGL BR 97 and CNPGL BR 40 presented the highest genetic gain for both damage score and chlorophyll content reduction, and then they will be selected to continue the B. ruziziensis breeding program with the possibility of maximizing genetic gain for the next generations.