Selección de las líneas de maíz por resistencia a sequía.

Abstract

Drought is an important abiotic factor where maize is grown under rainfall conditions. In order to identify drought resistant lines, 77 S5 maize lines from the breeding program at Cotaxtla, Veracruz and four CML maize lines from CIMMYTwere evaluated under irrigation (So) and drought stress (S1). Five indexes were applied to select drought tolerant lines. Four indexes use the grain yield as criteria for selection, these are, the drought index (DI), the arithmetic mean (AM), the geometric mean (GM), and the stress tolerance index (STI). The last index, (G+GxS), takes into consideration all the traits evaluated in the trial. In general, all measured characteristics were affected by the drought treatment. The DI the other indexes. DI selects germplasm with the lowest yields, while, AM, GM, STI and G+Gxs indexes selected the same lines and all of these displayed a superior mean yield in comparison to those that were selected by the DI index. Among the best 10%, five lines and the checks CML 273 y CML 274, were selected by most of the indexes. According with the results, the best option to select drought resistance material will be with the use of the G+GxS index.

Analysis of the Evolution of Drought through SPI and Its Relationship with the Agricultural Sector in the Central Zone of the State of Veracruz, Mexico

“…In general, this behavior is observed in most municipalities (Figure 5). Thus, the use of fertilizers, the adequate applications of agricultural practices, and the improvement in seeds generated a better corn yield in 2003-2018 [75][76][77][78][79][80][81][82].…”

“…Investigations have demonstrated that the temperature increases can cause a yield reduction not only in corn, but also in beans, strawberry, and potato production, which have experienced crop reductions from 20% to 50% [80][81][82][83][84][85][86][87][88][89][90][91][92][93][94]. For livestock, researchers found that growth, meat production, and milk (among others) are affected in warming environments [95].…”

Caracterización de genotipos élite de Coffea canephora por su tolerancia a sequía.

“…El índice de tolerancia a sequía se ha utilizado como criterio para seleccionar genotipos por su tolerancia al estrés. Dicho índice consiste en comparar los tratamientos sometidos a estrés de una variable, sobre aquellos en condiciones normales de riego (Castañón et al, 2000;González et al, 2005). Con este índice, se pueden considerar los genotipos con los valores más altos como los más tolerantes; aquellos con los valores más bajos serán los más susceptibles.…”