Tetraclinis articulata
(Vahl) Masters (Cupressaceae) is a woody tree species indigenous to North Africa. It is also found occasionally in Malta and Spain showing significant adaptability to different ...bioclimatic conditions. Due to its economic and ecologic values, this tree is affected by human and environmental disturbance leading to habitat fragmentation and genetic diversity loss. In this study, we aimed to promote the conservation of
T. articulata
, by measuring the allelic richness of a representative sample of 129 germplasms. Results showed differences in allele distribution. Inter–simple sequence repeat (ISSR) markers and the advanced maximization strategy implemented in PowerCore software were deployed to establish the first core collection of
T. articulata
. A core collection containing 10.07% out of the 129
T. articulata
germplasms was established. The representativeness of the core collection was evaluated and validated by different methods. The genetic diversity parameters or molecular traits (the observed number of alleles (Na), the effective number of alleles (Ne), Shannon’s information index (
I
), and Nei’s expected heterozygosity (He) showed similarities between the core collection and the entire collection averaging at Na = 1.712, Ne = 1.398,
I
= 0.395, and He = 0.253 and Na = 1.970 Ne = 1.363,
I
= 0.382, and He = 0.238, respectively. The analysis of molecular variance indicates that most of the genetic variation in
Articulata
core collections resided within populations (96%), with lesser amounts among populations (4%). Two clusters were identified with STRUCTURE and validated with unweighted pair group method with arithmetic mean dendrogram. The identified collection will be useful for conservation and breeding programs.
In Morocco, despite the adaptation of the prickly pear cactus (Opuntia spp) to edaphoclimatic conditions, differing from those that prevail in the countries from which it originates, this introduced ...species is regressing due to biotic and abiotic stresses that impact its survival. Hence, finding innovative technologies to preserve this species are essential. However, the success of in vitro micropropagation technologies is hinged upon the initial disinfection step. In this work we have tested several solutions and exposure time mixtures for disinfection across three different explants, as well as the adoption of hormonal combinations for the induction/regeneration step that allow for efficient micropropagation of cacti. We aimed to produce healthy regenerable vitroplants capable of effectively preserving themselves under aseptic conditions. We describe a specific protocol based on the type of areoles: (1) cladode without areolas (CWA); (2) areolas with shredded glochids (ASG); and (3) areolas with intact glochids (AIG). For each of these areoles, the disinfectant concentration and contact time were optimized and various hormonal combinations were tested for induction/regeneration. The optimal design meeting I-optimality criterion was used to predict the optimal combination by maximizing desirability. The disinfection combination that used 4.23% calcium hypochlorite (w:v), 0.4% Tween 20 (v:v), and 10 minutes of exposure time reduced the contamination frequency to 0.002% with a necrosis rate of less than 0.33% in explants with AIG. This type was the only one that gave responses in the induction/regeneration phase, which allowed us to predict the best rate of caulogenesis (71.74%) under a hormonal combination of 5.3 mg/L of BenzylAminopurine (BAP) and 0.59 mg/L of 1-Naphthaleneacetic acid (ANA). Furthermore, the highest callogenesis rate of 94.45% was obtained by a hormonal combination of 6 mg/L of BAP and 0.59 mg/L of ANA. The explant’s rhizognesis was carried out with a concentration of 0.5 mg / l ANA, before acclimatization on a substrate containing soil and sand in a ratio of 3:1. In conclusion, these protocols provide easy and cost-effective means to multiply cacti in vitro to preserve them in areas where their culture has been destroyed by cochineal.
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