Difference in the Ability of Initiation and Maintenance of Embryogenic Cultures among Sugi (Cryptomeriajaponica D. Don) Seed Families.

Abstract

Zygotic embryos of Cryptomeria japonica were collected from 20 clones and cultured on halfconcentration of Murashige and Skoog medium containing 10 u M 2, 4-dichlorophenoxyacetic acid to examine the differences in embryogenic tissue (ET) initiation among seed families. ETs were obtained in all the seed families tested, with an overall initiation rate of 45.6 % (689 from 1512 explants). However, initiation rates and maintenance rates differed considerably among seed families. They varied from 7.5 % to 78.5 % and from 1.2 % to 27.8 %, respectively.

Somatic Embryogenesis Initiation in Sugi (Japanese Cedar, Cryptomeria japonica D. Don): Responses from Male-Fertile, Male-Sterile, and Polycross-Pollinated-Derived Seed Explants

“…Even though different initial culture media and seed sources were used, the highest SE initiation frequencies in sugi (20–35%) with seeds collected in mid-July was also reported by Ogita et al [ 28 ]. Similarly, Taniguchi and Kondo [ 29 ] also reported that seeds collected in mid-July were the best explants for SE initiation in sugi, recording induction rates of up to 33.3%, testing 20 different families from the open-pollinated (OP) seed orchard.…”

Somatic embryogenesis in artificially pollinated seed families of 2nd generation plus trees and cryopreservation of embryogenic tissue in <i>Cryptomeria japonica</i> D. Don (Sugi)

“…From 2016 to 2018, 1857 immature seed explants (except those with microbial contamination), which were collected from 41 artificially pollinated seed families of 2nd generation C. japonica plus trees, were cultured for embryogenic tissues induction. Embryogenic tissue of C. japonica was white to translucent, moist and mucilaginous, and comprised small, dense embryonic cells and elongated, vacuolated suspensor cells (Taniguchi and Kondo 2000), like in other conifers (Jain et al 1995). The embryogenic tissue induction rate (i.e., the percentage of explants forming embryogenic tissue from cultured explants 3 months after the initial culture) in each of the 41 artificially pollinated seed families varied from 3.3 to 86.0% with mean of 38.4% (Figure 1).…”

“…The embryogenic tissue induction rate (i.e., the percentage of explants forming embryogenic tissue from cultured explants 3 months after the initial culture) in each of the 41 artificially pollinated seed families varied from 3.3 to 86.0% with mean of 38.4% (Figure 1). The embryogenic tissue induction rate of 1st generation plus trees ranged from 3.4 to 82.0% with mean of 45.6% in the open pollinated seed family (Taniguchi and Kondo 2000) and from 10 to 80% with mean of 46.6% in the artificially pollinated seed family (Taniguchi et al 2012). These results indicated that the embryogenic tissue induction rate range is comparable between 1st generation plus trees and 2nd generation plus trees, although the mean induction rate of 2nd generation plus trees is lower compared with 1st generation plus trees.…”

Somatic Embryogenesis and Plant Regeneration from Sugi (Japanese Cedar, Cryptomeria japonica D. Don, Cupressaceae) Seed Families by Marker Assisted Selection for the Male Sterility Allele ms1

“…The lowest average frequency, taking data for all four seed families into account, was recorded for the collection of July 03 (12.70%), this value increasing to 30.11% and 33.84% for collections taken on July 10 and July 24, respectively, and reaching the maximum value (42.24%) for seeds collected on July 18. An influence of seed collection date on the induction efficiency of embryogenic cells has been previously reported for male fertile sugi families [ 32 , 33 ] and other conifers [ 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 ]. The results of statistical analysis indicated that the proportion of the explants with SE initiation response significantly differed among families (χ 2 = 366.6, df = 3, p < 0.001) and among seed collection dates (χ 2 = 177.9, df = 3, p < 0.001).…”

“…Tissue culture as a tool for clonal propagation is an option to accelerate the breeding process for MSPs of sugi. Studies on micropropagation of sugi by tissue and organ culture have been reported since the 1970s [ 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 ], and recently reports on somatic embryogenesis (SE) as a plant regeneration system (including studies on the influence of plant material, explant collection time, explant genotype, and culture conditions as the main factors affecting SE) have been published [ 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 ]. However, tissue culture studies for male sterile sugi are limited to reports on micropropagation through shoot culture published by Fujisawa et al [ 40 ] and Ishii et al [ 41 ], and via SE reported by Maruyama et al [ 42 , 43 , 44 ].…”