Salinity effects on germination and seedlings biomass of Pachycereus pecten-aboriginum: an endangered species

Abstract

Cacti are particularly sensitive to habitat disturbance since they have slow growth and a longlife cycle. Their development and establishment depend on several factors, includingenvironmental requirements for germination and establishment of seedlings. Two of the mostinfluential factors are soil and water salinity. The objective of this study was to quantify seedsgermination and seedling biomass production of the Aborigine’s comb cactus (Pachyceruspecten-aboriginum) in salt stress using sodium chloride (NaCl) as the main salt source. Theexperiment was arranged in a completely randomized design using six salt levels (0.11, 2.03,4.00, 6.03, 8.03 and 10.07 dS m-1) with five replicates of 20 seeds each one. The seeds werecollected in a wild population of P. pecten-aboriginum in Ejido Álvaro Obregón, BajaCalifornia Sur, Mexico in June 2011. The results showed that germination and seedlingbiomass were significantly affected by salt stress, which was higher at 2.03 and 0.11 dS m-1,followed by 6.03 and 4.00 dS m-1, lower at 8.03 dS m-1, and no growth at 10.07 dS m-1. It isconcluded that saline levels using sodium chloride as the main source of salt, affect seedgermination and seedling biomass production of P. pecten-aboriginum significantly.

NaCl effect on germination and seedling fresh weight of Stenocereus eruca (Brandegee) A.C. Gibson & K.E. Horak

“…The experiment was developed under laboratory conditions a t the Universidad Autónoma of Baja California Sur located at 24° 08 ' 32" LN and 110° 18' 32" LW (INEGI, 2017). Stenocereus eruca seeds were treated with different salinity levels or electrical conductivities (0, 2, 4, 6, 8, and 10 dS m -1 ) following the same method carried out by Beltrán-Morales et al (2015).…”

“…Studies with cacti have demonstrated that increasing salt concentration impacts their germination percentage and seedling biomass production (Beltrán-Morales et al, 2015;Orozco et al, 2017). The effects of salinity on growth and production of young cladodes "nopalitos" (cladode sprouts) of Opuntia ficus-indica (L.) Mill., were investigated by Murillo-Amador et al (2001) using irrigation levels of NaCl with electrical conductivities of 2, 5, 10, 13, 18, and 21 dS m -1 .…”

Effect of salinity on seed germination, growth and metabolic activity of pitaya seedlings [Stenocereus thurberi (Engelm.) Buxb.]

“…In this regard, Beltran- Morales et al (2015) reported that germination of Pachycereus pectin-aboriginum seeds diminishes, as salinity concentration increases above 2.03 dSm -1 (1,300 ppm) NaCl. Thus, other species thriving in the region do not forcefully feature the same adaptation to salinity.…”

“…In addition to water scarcity, arid and semi-arid regions of the world, are exposed to a concomitant soil salinization (Schwabe et al 2006), which becomes another important factor restricting plants establishment, growth, and production (Beltrán- Morales et al 2015). Plants growing under saline stress, exhibit an increased energy expenditure to extract water from soils with negative osmotic potential, resulting in reduced cell expansion and tissue growth, decreased flow of assimilates to growing meristems and allowing inorganic ions accumulation (Morales et al 2002).…”