Drought Stress and Its Effects on Maize Reproductive Systems¹

Abstract

Moisture stress during pollination of maize (Zea mays L.) can greatly reduce kernel set, yet little quantitative information is available on the effects of plant water status on male and female floral development. The purpose of this study was to establish different drought stress regimes during pollination and to measure synchronization of male and female floral development, pollen viability, and diurnal silk elongation rates. Single cross hybrids were field‐grown in large pots and exposed to different soil moisture treatments at the time of tassel emergence. Compared to well‐watered control plants, mild (no visible wilting) and severe (visible wilting) drought treatments increased the interval from initial silking to initial pollen shed by an average of 3 and 4 days, respectively. Increasing moisture deficits caused no change in in vitro pollen germination even though the severest drought treatment caused visible symptoms of midday wilting and of lower leaf senescence. Diurnal silk elongation measurements indicated that on clear days the majority of silk elongation occurs at night when ear leaf water potentials are highest. At similar morning leaf water potentials, stressed plants maintained a lower silk elongation rate than well#x2014;watered plants. Positive silk elongation ceased at ear leaf water potentials of about #x2014; 9 bars in droughted plants and at #x2014; 14 bars in well—watered plants, suggesting that factors other than water potential may also regulate rate of silk growth. It is concluded that drought beginning at anthesis has a greater effect on female than male floral development.

Genome-Wide Analysis of Alternative Splicing during Development and Drought Stress in Maize

“…1B). This lack of response at the level of splicing is in keeping with the lack of strong phenotypic changes to tassel under drought (Herrero and Johnson, 1981). Ear growth is known to be strongly reduced under drought conditions (Boyer and Westgate, 2004), and large splicing differences based on drought treatment were observed (Fig.…”

Management of crop water under drought: a review

“…Brown et al 1989); (ii) early seeding shifts sensitive stages such as flowering and grain filling to periods of better water availability (e.g. Herrero and Johnson 1981); and (iii) deeper rooting of early sown crops improves avoidance of early droughts (Barraclough and Leigh 1984;Brown et al 1989;Incerti and O'Leary 1990). Ehlers and Goss (2003) reported higher yield of early sown winter wheat and winter barley on a light soil in the continental semi-arid climate of Eastern Germany.…”

“…Worland 1996;Campos et al 2004), inhibited pollination or seed abortion leading to reduced kernel number per ear/pod (e.g. Herrero and Johnson 1981;Ekanayake et al 1989;Gan et al 2004), as well as low single grain weight due to bad grain filling significantly reduce the sink capacity of grains and impair overall crop yield (e.g. Bolaños and Edmeades 1993;Blum 1998;Gooding et al 2003).…”

The maize Brown midrib1 locus affects cell wall composition and plant development in a dose-dependent manner

“…The water potential is known to affect flowering dynamics. In addition to a reduction in plant height (Sari-Gorla et al, 1999), drought conditions tend to result in increased silking delay (Moss and Downey, 1971;Herrero and Johnson, 1981). The silking delay, or anthesis-silking interval (ASI), refers to the time that elapses between pollen shedding and the appearance of silks on the ear of the same plant.…”