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Genotypic variation in patterns of root distribution, nitrate interception and response to moisture stress of a perennial ryegrass ( Lolium perenne L.) mapping population
Author(s) -
Crush J. R.,
Easton H. S.,
Waller J. E.,
Hume D. E.,
Faville M. J.
Publication year - 2007
Publication title -
grass and forage science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.716
H-Index - 56
eISSN - 1365-2494
pISSN - 0142-5242
DOI - 10.1111/j.1365-2494.2007.00583.x
Subject(s) - lolium perenne , edaphic , perennial plant , interception , moisture stress , biology , agronomy , population , water content , horticulture , soil water , ecology , demography , geotechnical engineering , sociology , engineering
Genotypic variation in patterns of root distribution, nitrate interception and response to moisture stress were assessed in both parents and 198 progeny of a perennial ryegrass ( Lolium perenne L.) full‐sibling mapping population. This was carried out in metre‐deep tubes of sand culture in a glasshouse experiment. The proportion of root dry matter (DM) weight in the top 10 cm of sand ranged from 0·33 to 0·75 and values of log 10 (1 − K ), where K is the constant for an exponential model relating root DM weight and root depth, also showed wide variation among genotypes. The proportion of a pulse of 15 N recovered in whole plants ranged from 0·124 to 0·431. There was a positive linear correlation between the proportion of 15 N recovered and plant total DM weight, but no relationship between nitrate interception and patterns of distribution of DM weight of roots. Some genotypes responded to moisture stress by increasing root growth, and in others root growth was inhibited. It is concluded that this below‐ground variability in root variables may be an evolutionary adaptation by plant populations to survive heterogeneity in soil biotic and edaphic factors.