Identification of Mexican maize races (Zea mays L.) with drought tolerance using osmotic potential experiments for genetic breeding
Laen...
Kuupäev
2023
Kättesaadav alates
Ajakirja pealkiri
Ajakirja ISSN
Köite pealkiri
Kirjastaja
Estonian University of Life Sciences
Abstrakt
Maize (Zea mays L.) is the third most important cereal crop worldwide after wheat and
rice per cultivated area with 249,225,876 hectares and the most important crop for number of
harvested grain tons with 1,482,997,259 in 2021. Some native Mexican maize races could be a
source for drought tolerance to improve commercial cultivars and hybrids. The experiments were
conducted using various osmotic pressures (OP) induced by polyethylene glycol (PEG-6000)
(0, -0.05, -0.15, -0.30 and -0.49 MPa) simulating an increase of drought stress in ten maize
genotypes. The main objectives of this study were the evaluation of germination and seedling
growth components in response to drought stress and the identification of sources of drought
tolerance in Mexican maize races. Apachito-r showed an increased germination in 110.4%,
Cristalino-079 had a decreased germination in 98.7% and Cristalino-279 reduced its germination
in a 91.1% compared to the control. Apachito-r outstands in root length at -0.05 OP increasing
200.1% and at -0.49 increasing 129.8%. The values for stem length were decreasing as the OP
was increasing and only Apachito-r showed a significant difference at -0.30 MPa decreasing
39.8% respect to its control. Cristalino-279 showed significant difference in the variable root
fresh weight and its value outstand at -0.15 increasing 267.2%, at -0.30 increasing 281.6% and at
-0.49 MPa increasing 189.3% compared to the control in water. The variable root dry weight had
the highest value for Apachito-r at -0.05 MPa increasing in a 189.4%, decreasing at -0.15 in 72%
and at -0.30 MPa in a 79.8% and increasing at -0.49 MPa in 112.3%. Also noteworthy are
E-zapata-r increasing 190.5% and Cristalino-061 increasing 142.9% at -0.30. E-zapata-r at -0.49
increased 115.1%. Cristalino-279 showed significant difference in the variable stem fresh weight
and its value outstand at -0.05, -0.15 and -0.30 MPa increasing 146.7%, 103.7% and 60.2%
respectively. Finally, in stem dry weight the tendency was to decrease as OP was increasing,
however Cristalino-279 showed differences at -0.30 decreasing in 89.5% and at -0.49 MPa
increasing in a 143.5% respect to the control. The most drought tolerant genotypes were
Cristalino-279, Apachito-r, Azul and 8-carreras-PP. The most tolerant genotypes showed greater
root length, greater root fresh and dry weight, better germination and greater stem length.
Resistant and susceptible genotypes are ideal material to understand the physical and chemical
mechanisms related to drought tolerance. Cristalino-279 shows the best level of drought tolerance
at all levels of osmotic pressure, this genotype can be used as a source of drought tolerance for
the improvement of commercial maize.
Kirjeldus
Received: July 13th, 2023 ; Accepted: September 23rd, 2023 ; Published: October 23rd, 2023 ; Correspondence: cruz2477@yahoo.com.mx
Märksõnad
native maize races, drought tolerance, osmotic pressure, polyethylene glycol, articles