Maize susceptibility to drought at flowering: a new approach to overcome the problem

Abstract

Among the agronomically important grasses, maize is the most susceptible to drought at flowering. Drought stimulates a protandrous pattern of development, increasing the anthesis-silking interval. Because maize has a short period of flowering and pollen remains viable for only a short period of time, each day of delay between pollen shed and silk emergence will reduce the rate of sexual fertilization and increase barrenness. The purpose of this article is to present an ideotype of maize designed to overcome this problem. The biological model described here can reduce sensitivity to water deficiency through morphological and anatomical modifications, such as the transference of the ear from the axil of a leaf to the apex of the plant; condensation of the upper stem internodes; and a reduction of plant height and leaf number. Genetic diversity was found for all traits of interest. It was possible to identify and select mutants that exhibited the proposed alterations in a single phenotype. However, associated with those mutants there were several undesirable characteristics, such as lack of vigor and disease susceptibility. To gain an agronomically acceptable phenotype with adaptation to a hot and dry environment further improvement is needed.

Global synthesis of drought effects on cereal, legume, tuber and root crops production: A review

“…4). Wheat is a monoclinous monoecious plant where the anthers and ovaries develop in the same flower while maize is a diclinous monoecious plant in which competition for water between female and male flowers occurred (Sangoi and Salvador, 1998). As drought favored the development of male rather than female inflorescence (Sangoi and Salvador, 1998), it created significant fertilization failures.…”

“…Wheat is a monoclinous monoecious plant where the anthers and ovaries develop in the same flower while maize is a diclinous monoecious plant in which competition for water between female and male flowers occurred (Sangoi and Salvador, 1998). As drought favored the development of male rather than female inflorescence (Sangoi and Salvador, 1998), it created significant fertilization failures. The negative effects of water stress on rice was caused by pollen 1 8 sterility, due to impairment of sugar metabolism and starch synthesis of the mother cell during meiosis (Sheoran and Saini, 1996).…”

Understanding Plant Density Effects on Maize Growth and Development: An Important Issue to Maximize Grain Yield

“…Because the tassel is apical and differentiates first, it has developmental priority over the ears (SANGOI & SALVADOR, 1998b). This protandrous behavior is accentuated at high plant densities, assuring pollen production and dispersion at the expense of ear and silk development (SANGOI & SALVADOR, 1998c).…”

Metabolite profiles of maize leaves in drought, heat and combined stress field trials reveal the relationship between metabolism and grain yield

“…The negative effect of DS on maize yield is especially acute during the reproductive stage between tassel emergence and early grain filling (Grant et al, 1989), when it is believed to induce premature seed desiccation and to limit grain filling. Grain is more susceptible to DS than vegetative tissues; therefore, the prediction of grain yield from the physiological parameter of leaves is a challenge (Sangoi and Salvador, 1998;Khodarahmpour and Hamidi, 2011). Nevertheless, maize yield is dependent on both the assimilate supply to the kernel (source) and the potential of the kernel to accommodate this assimilate (sink potential; Jones and Simmons, 1983).…”