Investigation of mechanism of leaf growth inhibition in maize

Abstract

The mechanism of leaf growth inhibition was investigated in eight maize genotypes differing in drought resistance and maturity groups. In controlled conditions the effects of drought, nitrogen deficiency, pH and ABA on leaf growth were investigated. In soil drying experiment measurements of water potential and its components and leaf growth and development parameters were carried out. The same parameters of leaf growth and development were measured in nitrogen deficiency experiment, while leaf growth was measured in pH and ABA experiments. In field experiment n3easurement parameters of plant growth and productivity were done. Obtained results pointed out that hydraulic and chemical signaling regulated the leaf growth under drought conditions. Drought decreased leaf growth in all genotypes and resistant lines from both maturity groups showed faster leaf development. Water deficit affected cell production and elongation with significant genotypic differences. A similar phenomenon was observed with nitrogen deficiency. Effect of alkalization of 'artificial xylem sap' and application of exogenous ABA (10-6 and 10-8 M) on reduction of leaf growth was more expressed in susceptible line. Analysis of growth and productivity in field conditions showed that drought had smaller effect on inhibition of leaf growth in resistant genotypes, which had consequences on the yield of these plants.

Mehanizam inhibicije rastenja listova ispitivan je kod osam genotipova kukuruza različite otpornosti na sušu i iz različitih grupa zrenja. U kontrolisanim uslovima ispitivan je efekat suše, nedostatka azota, pH i ABA na rastenje listova. U eksperimentu sa sušom urađena su merenja vodnog potencijala i njegovih komponenti i parametara rastenja i razvića lista. Isti parametri rastenja i razvića lista mereni su u eksperimentu sa nedostatkom azota, dok je rastenje lista mereno u eksperimentu sa pH i ABA. U poljskom eksperimentu mereni su parametri rastenja biljaka i produktivnosti. Dobijeni rezultati pokazuju da hidraulička i hemijska signalizacija reguliše rastenje listova u uslovima suše. Suša smanjuje rastenje listova kod svih genotipova i otporne linije na sušu pokazuju brže lisno razviće. Vodni deficit utiče na produkciju i elongaciju ćelija sa značajnim genotipskim razlikama. Sličan fenomen je utvrđen pri nedostatku azota. Efekat alkalizacije rastvora 'veštačkog ksilemskog soka' i aplikacije egzogene ABA (10-6 i 10-8 M) na redukciju rastenja listova vise je izražen kod linije neotporne na sušu. Analiza rastenja i produktivnosti biljaka u poljskim uslovima pokazala je da je suša imala mali efekat na inhibiciju rastenja listova kod otpornih genotipova, što se odrazilo na prinos tih biljaka.