In vitro propagation of pecan [Carya illinoinensis (Wangenh) K. Koch]

Abstract

The pecan [Carya illinoinensis (Wangenh.) K. Koch], a member of the family Juglandaceae, is an economically important nut crop. Propagation of pecan is done primarily by budding or grafting of improved cultivars onto seedling rootstocks. However, these methods suffer disadvantages such as considerable time, expense and poor transplanting survival of the plants. Propagation by cutting, though leads to uniform clonal rootstocks, is very difficult as the clones do not root readily. Even with the use of hormones, inconsistent results with only limited improvements have been reported (Brutsch et al. 1977;Smith et al. 1974;Wolstenholme and Allan 1975). In vitro propagation offers great potential for the pecan industry for large scale multiplication of selected clones and enables production of a high amount of constant quality plantlets within a very short time. Although somatic embryogenesis has been developed for pecan (Mathews and Wetzstein 1993;Merkle et al. 1987;Wetzstein et al. 1989Wetzstein et al. , 1990Yates and Reilly 1990), successful pecan micropropagation was not achieved because of poor regeneration and rooting. Wood (1982) and Knox and Smith (1981) have used nodal stem segment explants from seedlings to establish shoot proliferation, however, no consistent shoot proliferation, elongation or root development occurred and no plants were established in soil. Phillips and Ramirez (1983) and Corte-Olivares et al. (1990) used apical and axillary buds; shoot elongation was obtained, but rooting and establishment of plantlets were poor. Hansen and Lazarte (1984) used nodal cuttings as explants; shoots were rooted with 93% success and 63% plants were established in soil while Corte-Olivares et al. (1990) obtained 40% rooting of shoots. In this article, we report the development of a reliable and efficient protocol for rapid in vitro shoot induction and rooting of pecan plants by culturing nodal explants from seed in liquid culture. Although micropropagation of pecan through nodal explants from seed will result in heterozygous plants, the protocol optimized in this study could be applied for producing true-type plants from mature tissues.The unshelled mature seeds of pecan cultivars 'Cape Fear' and 'Desirable' were washed with sterile water for 10 min and then sterilized by immersion in the carbendazim solution (1.0 g l Ϫ1; Sigma Chemical Co., St. Louis, MO, USA) overnight. The seeds were washed with sterile water and treated with 70% ethanol for 30 min., again washed with sterile water for three times to remove ethanol. Subsequently, the seeds were treated with a 2.83% (w/v) sodium hypochlorite for 30 min. The seeds were thoroughly rinsed five times with sterile water and aseptically shelled using nut cracker. The embryos were aseptically isolated from the seeds and treated with 2.83% (w/v) sodium hypochlorite solution for 10 min. and rinsed with sterilized water five times for five min Abstract An efficient method for in vitro propagation has been developed for pecan [Carya illinoinensis (Wangenh) K. Koch], a hig...

Advances in Micropropagation of Commercial Pecan Cultivars

“…For proliferation, an experiment was conducted as completely randomized design with three replications and 16 jars as plot and four shoots in each. The new tissue culture shoots from healthy, non-contaminated and without brown symptoms of explants from the establishment phase (Figure 2a,b) were excised and cultured on DKW medium supplemented with different concentrations of BA (4.44,13.3,22.20,and 44.4 µM) for determination of the medium giving the best proliferation rate (Renukdas et al, 2010) (Figure 2c). The average number of shoots was assessed after 28 days of culturing.…”

“…The main advantage for having self-rooted pecan cultivars is to speed propagation (1 versus 3 years), and most likely lower production costs of the propagated tree. In our knowledge, there is no literature showing selfrooted trees of pecan being more or less vulnerable to biotic or abiotic stresses (Casales et al, 2018;Garner, 2011;Renukdas et al, 2010) Early reports of pecan cultivars tissue culture include Smith (1977) but neither was successful in establishing plants in soil. Major issues in micropropagation of pecan have included poor rooting and poor survival after transplanting to the greenhouse (Brutsch et al, 1977).…”

“…Results of this preliminary study indicated that some adult pecan phenotypes had potential for clonal micropropagation. Renukdas et al (2010) used nodal explants of 'Desirable' and 'Cape Fear' seedlings and at least nine multiple shoots per explants were obtained after three weeks of culture. The multiple shoots were successfully rooted and transferred to peat pellets and subsequently to the greenhouse.…”

“…We believe it is significant that the publications do not include methods for introduction of mature cultivars into culture. The ability to micropropagate juvenile material has not translated into the ability to micropropagate clonal mature cultivars (Renukdas et al, 2010). Thus, we believe this research is relevant to the scientific community, as it describes for the first time methods to micropropagate multiple cultivars.…”

Phytochemical, Elemental and Biotechnological Study of Cryptocarya Latifolia

“…This indicates the influence of PGRs in shoot induction and has been reported in other studies (Hudson et al, 2002;Renukdas et al, 2010). However, the number of explants forming shoots in BB1, BB2 and BB3 were lower (41%, 71% and 52%, respectively) than the number of explants treated with combination PGRs i.e.…”