Root Growth of Wheat Genotypes in Hydroponic Culture and in the Greenhouse under Different Soil Moisture Regimes

Abstract

Root characteristics of wheat (Triticum aestivum L.) genotypes are believed to be important in tolerance to drought and flooding, yet neither the extent of differences in root size among modern soft red wheat cultivars nor the degree of association between root size and drought or flooding tolerance is known. This study was conducted to see whether genotypes differ in root size, and to see if root size is associated with tolerance to flooded soil and to drought during early vegetative growth. We found differences in root fresh weight (RFW), shoot fresh weight (SFW), number of roots longer than 40 cm (NR), longest root length (LRL) and total root length (TRL) of 40 winter wheat genotypes grown in hydroponic culture for 4 wk. Each of these parameters was positively correlated with all others. Twelve genotypes with different root sizes selected from these 40 were grown in a greenhouse soil experiment for 3 wk, after which soil moisture treatments of control, flooding, and drought were imposed for a period of 21 d. Flooding did not affect SFW and number of tillers (NT), but decreased RFW. Drought drastically decreased all three parameters. The genotype × moisture treatment interactions for SFW, RFW, and NT were significant. Root and shoot growth of these genotypes in hydroponic culture were correlated to their root and shoot growth under both control and flooded conditions, but not under drought. Thus, it appears that the expression of genotypic root growth potential may be influenced by the availability of soil moisture, and that selection of wheat seedlings for vigorous growth in hydroponic culture will select for vigorous early growth in soil with adequate or excess moisture, but not under severe drought.

Evaluation of morphological characteristics in Venezuelan maize (Zea mays L.) genotypes under drought stress

“…Cargill-163 showed the lowest RFW (2.05 g), while the other nine genetic materials presented higher root fresh weight, with no statistical differences among them. Drought drastically decresead RFW in winter wheat genotypes grown in greenhouse container culture for 3 weeks (MIAN et al, 1993). The trend demonstrated by Cargill-163 may be indicative of a sensitive genotype to drought stress.…”

“…Over the years, physiological and morphological characteristics such as osmotic adjustment, stomatal behaviour, chloroplast activity, leaf water potential, root volume, root weight, leaf area, dry matter production, have been studied in several maize cultivars grown under limited water supply (MUSICK et al, 1965;SANCHEZ-DIAZ & KRAMER, 1971;NASS & ZUBER, 1971;MORGAN, 1984;WEERATHAWORN et al, 1992;MIAN et al 1993). It has been shown that maize has low drought tolerance due its high transpiration surface and poor root system (MALHERBE, 1964).…”

Crescimento inicial e absorção de nutrientes pelo algodoeiro cultivado sobre a palhada de Brachiaria ruziziensis

“…Resultados similares foram ralatados por Mian et al (1993), em que o crescimento radicular vigoroso resultou em crescimento vigoroso da parte aérea do trigo, por Girdthai et al (2010), em amendoim, e por Kennedy & Hutchinson (1999), em algodão. Isso leva a crer que a cultura tende a manter equilíbrio na sua relação raiz/parte aérea; a ocorrência de prejuízos em um dos fatores será acompanhada de redução do outro fator.…”

Effects of a Reduction in Soil Moisture from One Month beforeFlowering through Ripening on Dry Matter Production and Ecophysiological Characteristics of Wheat Plants

“…The development of root system can be promoted under moisture-defi cient conditions, even though it depends on the strength of the drought (Eghball and Maranville, 1993) and on both the species and the variety of plants Hida et al, 1995;Huang et al, 1997). A well-developed root system has also been reported in wheat plants grown under lower soil-moisture conditions (Proffi tt et al, 1985;Mian et al, 1993;Nakamura et al, 2003).…”