Crop wild relatives of pigeonpea [Cajanus cajan (L.) Millsp.]: Distributions, ex situ conservation status, and potential genetic resources for abiotic stress tolerance
Khoury, C.K. ; Castaneda-Alvarez, N.P. ; Achicanoy, H.A. ; Sosa, C.C. ; Bernau, V. ; Kassa, M.T. ; Norton, S.L. ; Maesen, L. ; Upadhyaya, H.D. ; Ramirez-Villegas, J. ; Jarvis, A. ; Struik, P.C. - \ 2015
Biological Conservation 184 (2015). - ISSN 0006-3207 - p. 259 - 270.
species distribution models - global food security - male-sterility - climate-change - osmotic adjustment - diversity - bias - biodiversity - adaptation - accessions
Pigeonpea [Cajanus cajan (L.) Millsp.] is a versatile, stress-tolerant, and nutritious grain legume, possessing traits of value for enhancing the sustainability of dry sub-tropical and tropical agricultural systems. The use of crop wild relatives (CWR) in pigeonpea breeding has been successful in providing important resistance, quality, and breeding efficiency traits to the crop. Current breeding objectives for pigeonpea include increasing its tolerance to abiotic stresses, including heat, cold, drought, and waterlogging. Here we assess the potential for pigeonpea CWR to be further employed in crop improvement by compiling wild species occurrence and ex situ conservation information, producing geographic distribution models for the species, identifying gaps in the omprehensiveness of current germplasm collections, and using ecogeographic information to identify CWR populations with the potential to contribute agronomic traits of priority to breeders. The fifteen prioritized relatives of pigeonpea generally occur in South and Southeast Asia to Australia, with the highest concentrations of species in southern India and northern Australia. These taxa differ considerably among themselves and in comparison to the crop in their adaptations to temperature, precipitation and edaphic conditions. We find that these wild genetic resources are broadly under-represented in ex situ conservation systems, with 80% of species assessed as high priority for further collecting, thus their availability to plant breeders is insufficient. We identify species and highlight geographic locations for further collecting in order to improve the completeness of pigeonpea CWR germplasm collections, with particular emphasis on potential traits for abiotic stress tolerance.
East African highland bananas (Musa spp. AAA-EA) 'worry' more about potassium deficiency than drought stress
Taulya, G. - \ 2013
Field Crops Research 151 (2013). - ISSN 0378-4290 - p. 45 - 55.
foliar nutrient status - biomass allocation - osmotic adjustment - plant-growth - root ratio - soil-water - nitrogen - shoot - fertilizer - weevil
Drought stress, potassium (K) and nitrogen (N) deficiencies are major constraints to rain-fed East African highland banana (EAHB) production in Uganda. It was hypothesised that the reduction in fresh bunch mass and increase in dry matter (DM) allocation to corms with drought stress, K and N deficiency is additive. Individual plant measurements at harvest from two field trials in central and south western Uganda were analyzed to evaluate effects of cumulative rainfall (CRF) received 365 days from sucker emergence, mineral K and N inputs on EAHB bunch yields. Dry matter content in aerial shoot (leaves and pseudostems) relative to that in the subterranean corm was also analyzed to evaluate DM allocation plasticity due to drought stress, K and N deficiency. This was verified with allometric analysis using pre-harvest stage plants from farms of known K and N nutritional status and plants from a screen house drought stress pot trial in Uganda. Dry matter production and yields were mainly driven by K interacting with CRF. Within 12 months, K input (250-600 kg K ha(-1) yr(-1)) increased bunch yield from 8 to 15 Mg ha(-1) yr(-1) irrespective of whether dry (CRF <1100 mm) or wet (CRF >= 1100 mm) conditions prevailed, possibly due to K-mediated osmotic adjustment under dry conditions. Without K input, wet conditions increased bunch yield from 6 to 8 Mg ha(-1) yr(-1) while dry conditions decreased it from 6 to 4 Mg ha(-1) yr(-1) within 12 months. Total DM and its distribution between the biomass structures followed similar trends. Nitrogen input (150-400 kg N ha(-1) yr(-1)) neither affected bunch yield nor DM allocation at harvest stage. At pre-harvest stage, reduction in DM allocation to the corm per unit increase in total DM was 14-22% significantly lower with N and/or K deficiency compared with that under sufficient K and N. Drought stress per se had no effect on DM allocation but enhanced DM allocation shifts due to K deficiency. Drought-stressed EAHB thus increase DM allocation to subterranean structures only if K-deficient, unlike responses reported for other plant species. Potassium nutrition is perhaps a more viable entry point for mitigation of drought stress in EAHB cropping systems than irrigation but this requires further agronomic and economic evaluation. It may be important to account for carbon allocated to osmotic adjustment for realistic simulation of water- and K-limited growth in EAHB. (c) 2013 Elsevier B.V. All rights reserved.
Modelling the effects of soil water potential on growth and quality of cut chrysanthemum (Chrysanthemum morifolium)
Lin, L. ; Li, W. ; Shao, J. ; Luo, W. ; Dai, J. ; Yin, X. ; Zhou, Y. ; Zhao, C. - \ 2011
Scientia Horticulturae 130 (2011)1. - ISSN 0304-4238 - p. 275 - 288.
winter-wheat production - dry-matter production - crop growth - leaf-area - night temperature - flower characteristics - osmotic adjustment - simulation-model - balance model - whole-plant
A complete dynamic model was developed to describe the effects of soil water potential (WP) on the growth and external quality of standard cut chrysanthemum (Chrysanthemum morifolium) in order to optimise water management of greenhouse crops. Experiments using chrysanthemum cv. ‘Jinba’ with different planting dates and levels of water treatment were conducted in a lean-to type greenhouse from 2006 to 2008. The dynamics of leaf area index (LAI), dry matter partitioning, and external quality traits (plant height, number of leaves per plant, flower-head diameter and peduncle length) were first determined as functions of accumulated photothermal index (PTI). Impacts of WP on leaf photosynthetic rate, LAI, dry matter partitioning, and the external quality traits were quantified via introducing the experimentally identified effects of WP on the parameters in the light response curve of leaf photosynthetic rate and the PTI-based functions. These quantitative relationships were incorporated into a generic crop growth model SUCROS. Using independent experimental data, the model was found to give good predictions for biomass production, dry weight of organs, and the external quality traits of the chrysanthemum cultivar grown under different levels of water supply. The coefficient of determination (r2) between the predicted and measured results was 0.91 for LAI, 0.88 for biomass production, and varied between 0.83 and 0.93 for organ dry weight and the external quality traits. Further evaluation is needed when applying this model to a wider range.
Moderate water stress affects tomato leaf water relations in dependence on the nitrogen supply
Garcia, A.L. ; Marcelis, L.F.M. ; Garcia-Sanchez, F. ; Nicolas, N. ; Martinez, V. - \ 2007
Biologia Plantarum 51 (2007)4. - ISSN 0006-3134 - p. 707 - 712.
gas-exchange - stomatal conductance - drought resistance - osmotic adjustment - growth - plants - nutrition - accumulation - responses - genotypes
The responses of water relations, stomatal conductance (g(s)) and growth parameters of tomato (Lycopersicon esculentum Mill. cv. Royesta) plants to nitrogen fertilisation and drought were studied. The plants were subjected to a long-term, moderate and progressive water stress by adding 80 % of the water evapotranspirated by the plant the preceding day. Well-watered plants received 100 % of the water evapotranspirated. Two weeks before starting the drought period, the plants were fertilised with Hoagland's solution with 14, 60 and 110 mM NO3- (N14, N60 and N110, respectively). Plants of the N110 treatment had the highest leaf area. However, g(s) was higher for N60 plants and lower for N110 plants. At the end of the drought period, N60 plants showed the lowest values of water potential (Psi(w)) and osmotic potential (Psi(s)), and the highest values of pressure potential (Psi(p)). N60 plants showed the highest Psi(s) at maximum Psi(p) and the highest bulk modulus of elasticity.
Salt tolerance analysis of chickpea, faba bean and durum wheat varieties. I. Chickpea and faba bean
Katerji, N. ; Hoorn, J.W. van; Hamdy, A. ; Mastrorilli, M. ; Oweis, T. - \ 2005
Agricultural Water Management 72 (2005)3. - ISSN 0378-3774 - p. 177 - 194.
soil-salinity - osmotic adjustment - grain legumes - water-stress - growth - yield - drought
Two varieties of chickpea (Cicer arietinum L.) and faba bean (Vicia faba), differing in drought tolerance according to the classification of the International Center for Agronomic Research in Dry Areas (ICARDA), were irrigated with waters of three different salinity levels in a lysimeter experiment to analyse their salt tolerance. The drought-sensitive varieties are more salt tolerant than the drought-tolerant varieties. Under saline conditions, the drought-sensitive varieties show a much higher yield up to a salinity threshold, corresponding with an electrical conductivity (ECe) between 2.5 and 3 dS/m for chickpea and between 5.5 and 6 dS/m for faba bean. The drought-sensitive varieties are able to improve or maintain the water-use efficiency when irrigated with saline water. This ability can be ascribed to • the larger biomass production owing to the later senescence, which allows a better utilization of the irrigation water; • the late flowering of chickpea.
Salt tolerance analysis of chickpea, faba bean and durum wheat varieties. II. Durum wheat
Katerji, N. ; Hoorn, J.W. van; Hamdy, A. ; Mastrorilli, M. ; Nachit, M.M. ; Oweis, T. - \ 2005
Agricultural Water Management 72 (2005)3. - ISSN 0378-3774 - p. 195 - 207.
osmotic adjustment - drought - adaptation - plants
Seven varieties of durum wheat (Triticum turgidum), provided by ICARDA, were tested in a greenhouse experiment for their salt tolerance. Afterwards two varieties, differing in salt tolerance, were irrigated with waters of three different salinity levels in a lysimeter experiment to analyse their salt tolerance. The characteristics of the salt tolerant variety compared to the salt sensitive variety are: - a shorter growing season and earlier senescence; - a higher pre-dawn leaf water potential; - a stronger osmotic adjustment; - a better maintenance of the number of productive stems per plant. Salt tolerance of durum wheat corresponds with drought tolerance because the tolerance is caused by earlier senescence and stronger osmotic adjustment, both reducing the transpiration of the plant
Salinity effect on crop development and yield, analysis of salt tolerance according to several classification methods
Katerji, N. ; Hoorn, J.W. van; Hamdy, A. ; Mastrorilli, M. - \ 2003
Agricultural Water Management 62 (2003). - ISSN 0378-3774 - p. 37 - 66.
bodemzoutgehalte - opbrengsten - zouttolerantie - evapotranspiratie - modellen - soil salinity - evapotranspiration - yields - salt tolerance - models - early seedling growth - stress day index - water-stress - soil-salinity - stomatal conductance - osmotic adjustment - maize - drought - plant - nodulation
The publication is a synthesis of previous publications on the results of a long-term lysimeter experiment. From 1989 to 1998, the experimental variables were soil salinity and soil type, from 1999 onwards, soil salinity and crop variety. The plant was studied during the whole growing period by measuring the saline stress and analyzing its effect on leaf area and dry matter development and on crop yield. Salinity affected the pre-dawn leaf water potential, stomatal conductance, evapotranspiration, leaf area and yield. The following criteria were used for crop salt tolerance classification: soil salinity, evapotranspiration deficit, water stress day index. The classification according to soil salinity distinguished the salt tolerant group of sugar beet and wheat, the moderately salt sensitive group comprising broadbean, maize, potato, soybean, sunflower and tomato, and the salt sensitive group of chickpea and lentil. The results for the salt tolerant and the moderately salt sensitive groups correspond with the classification of Maas and Hoffman, excepted for soybean. The evapotranspiration deficit criterion was used, because for certain crops the relation between yield and evapotranspiration remains the same in case of drought and salinity. This criterion, however, did not appear useful for salt tolerance classification. The water stress day index, based on the pre-dawn leaf water potential, distinguished a tolerant group, comprising sugar beet, wheat, maize, sunflower and potato, and a sensitive group, comprising tomato, soybean, broadbean, chickpea and lentil. The classification corresponds with a difference in water use efficiency. The tolerant crops show a more or less constant water use efficiency. The sensitive crops show a decrease of the water use efficiency with increasing salinity, as their yield decreases stronger than the evapotranspiration. No correlation could be found between osmotic adjustment, leaf area and yield reduction. As the flowering period is a sensitive period for grain and fruit formation and the sensitive crops are all of indeterminate flowering, their longer flowering period could be a cause of their greater sensitivity. The tolerant group according to water stress day index can be divided according to soil salinity in a salt tolerant group of sugar beet and wheat and a moderately sensitive group, comprising maize, sunflower and potato. The difference in classification can be attributed to the difference in evaporative demand during the growing period. The sensitive group according to water stress day index can be divided according to soil salinity in a moderately sensitive group, comprising tomato, soybean and broadbean, and a salt sensitive group of chickpea and lentil. The difference in classification can be attributed to the greater salt sensitivity of the symbiosis between rhizobia and grain legume in the case of chickpea and lentil. (C) 2003 Elsevier Science B.V. All rights reserved.