• Journal of Plant Biology
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• v.11 no.1
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• pp.27-32
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• 1968

In the present experiment as a basic study for establishing a hybrid seed orchard, an observation was made on the survivability of grafts using Pinus rigida as the stock and its hybrids as the sciion, and on the shape and germination of pollen collected from grafted plants. The results are summarized as follows: 1. The hybrid scion of P. rigida.taeda or $P. rigida{\times}(P. rigida.taeda)$ grafted into P. rigida stock showed lower survivability than the homoplastic graftings of P. rigida. 2. Five among the eight eleven-year old scions homoplastically grafted into two-year old stock for the staminate strobile one year after their grafting. 3. There was no difference in the size and germination ability between the pollen collected from homoplastically grafted plant and from the normal one. 4. The pollen collected from the grafted plant is thought to be usable for the control pollination as the germination of such pollen was considerably good.

• Journal of Korean Society of Forest Science
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• v.64 no.1
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• pp.47-51
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• 1984

Hybrids among some southern pines, Pinus rigida, Pinus taeda and Pinus serotina, were tested in Chunbuk area in order to investigate their adaptability to Korean climate and soils. The results were summarized as follows; 1) Hybrids between P. rigida and P. raeda showed good growth among interspecific hybrids of southern pines tested. In particular, P. taeda${\times}$P. rigida showed remarkable growth in Chunbuk area. 2) The survival rate of P. taeda was extremely low, probably because of cold susceptibility. 3) Volume growth was correlated with width and length of cone, length of needle and needle sheath at the 1% level. 4) Hybrids were generally located between the parents in cluster analysis.

• Journal of Korean Society of Forest Science
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• v.94 no.6
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• pp.402-409
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• 2005

This study was undertaken to compare and estimate the severity of pitch canker of individual trees of Pinus rigida and Pinus rigida ${\times}$ P. taeda in two seed orchards in Jeju island, in which the orchards have been damaged by the pitch canker for seven years. Wind-pollinated two-year-old seedlings of P. rigida and P. rigida ${\times}$ P. taeda, in which the seedlings of P. rigida ${\times}$ P. taeda were from seeds of phenotypically selected, uninfected(but untested) trees, were inoculated with the pathogenic fungus, Fusarium circinatum, isolated from P. rigida and P. thunbergii. The virulence of the isolates was also identified. Statistically significant difference was found in 'stem cankers'(SC; ${\chi}^2=7.76$, P=0.05) among 4 plantations of P. rigida ${\times}$ P. taeda of two seed orchards. P. rigida was higher in 'top kill' (TK) and 'branch tip symptoms' (BT) than those of P. rigida ${\times}$ P. taeda. In artificial inoculation tests, mortality of the seedlings from the resistant candidates was 14% higher than that of the seedlings from the susceptible candidates. This result may becaused by unknown pollen trees and/or candidate tree selection based only on phenotype. Two of five fungal isolates, C-6-L(9) and C-6-L(19), showed significantly higher mortality (68% and 60%, respectively) than others, suggesting that these isolates can be used as virulent isolates for a mass artificial inoculation. Resistance candidate seedlings that were selected from this study can be utilized as useful materials for fundamental studies of genetics and biochemistry to breed resistance varieties to pitch canker.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2023.04a
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• pp.55-55
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• 2023

With the COVID-19 pandemic, there is increasing interest in anti-obesity strategies. According to the National Statistical Office, the obesity rate in Korea was 38.3% in 2020 and 37.1% in 2021. Obesity is a risk factor for several severe diseases, including stroke, heart disease, type 2 diabetes, and certain types of cancer. Pinus rigida × Pinus taeda is a hybrid of Pinus rigida Mill and Pinus taeda Linn, and its cones are considered a by-product. Although previous studies have investigated their pharmacological effects on antioxidant activity and protection against oxidative DNA damage, few researchers have explored their potential as functional natural materials. Therefore, we evaluated the anti-obesity effects of the cone of ethyl acetate fraction of P. rigida × P. taeda (ERT), specifically its ability to inhibit lipid accumulation. Our analysis showed that ERT contains phytochemicals (catechin and caffeic acid) which are known to improve immune function and inhibit cell damage. ERT inhibited lipid droplet accumulation at the cellular levels through Oil Red O staining. Furthermore, ERT suppressed the expression of adipogenic transcription factors (PPARγ and CEBP/α) as well as downstream lipogenic target genes (FAS and SREBP-1) thereby inhibiting adipogenesis. ERT also down-regulated key adipogenic markers, including aP2α, while inducing the phosphorylation of AMPK. It has been reported that PPARγ and CEBP/α are expressed in the early stages of adipose differentiation, while SREBP-1 is expressed in the late stage. Therefore, our findings suggest that ERT activates AMPK signaling pathways, which inhibits adipogenic transcription factors (PPARγ, C/EBPα, and SREBP1) and lipogenic genes (FAS and aP2α), thereby blocking lipid accumulation and preventing obesity and related disorders. ERT showed potential as a new resource for developing a functional material for anti-obesity agents.

• Journal of Korean Society of Forest Science
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• v.82 no.4
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• pp.319-327
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• 1993

The objectives of this study were to isolate ectomycorrhizal fungi associated with roots of Pinus rigida ${\times}$ P. taeda trees planted in Chonbuk and Daejon locations and to identify them, and to observe the morphology of mycorrhizae formed by the isolated fungi. Pinus rigida ${\times}$ P. taeda seedlings formed ectomycorrhizae with Rhizopogon rubescens, Rhizopogon sp. and Suillus pictus isolated from the roots of mature Pinus rigida ${\times}$ P. taeda trees, Pinus rigida ${\times}$ P. taeda seedlings formed ectomycorrhizae with Pisolithus tinetorius too. The root surface of inoculated seedlings was covered with mycelia, and Hartig net were well developed in those roots. The size of vacuole was small, and the protoplasm was planty in ectomycorrhizal cell, compared to nonmycorrhizal cell. But the size of nuclei are not changed even in ectomycorrhizal cell.

• Journal of Korean Society of Forest Science
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• v.69 no.1
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• pp.28-35
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• 1985

To estimate the aboveground biomass of Pinus rigida and Pinus rigida ${\times}$ taeda 22-year-old plantations, the experimental plots of $200m^2$ in size located in Kwangju of Jeonlanam-do were selected. Nine sample trees selected at each plot taking account of DBH distribution were felled and the diagram of oven-dry weight distribution of stem, branch, and needle for each 1m segment was constructed. The logarithmic regression equations between dry weight of each component (stems, branches, and needles) and the variable of $(DBH)^2{\cdot}H$ were obtained. The aboveground standing crops was estimated to be as much as 71.61 and 142.32 tons of dry matter per hectare in P. rigida and P. rigida ${\times}$ taeda stand respectively. The net production was estimated as 10.81 and 10.46 t/ha/yr and the net assimilation rate 1.32 and 1.00 kg/kg/yr in P. rigida and P. rigida ${\times}$ taeda stand respectively. And the efficiency of needles to produce stem was 0.97 and 0.81 kg/kg/yr in same order.

• Journal of Korean Society of Forest Science
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• v.63 no.1
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• pp.42-50
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• 1984

Photosynthetic ability and net assimilation rate were compared between two-year-old seedlings of Pinus rigida and of Pinus rigida ${\times}$ P. taeda $F_1$ to examine whether growth potential could be predicted at young stages. Six families per each species used in this study were grown at the nursery of the Institute of Forest Genetics in Suweon. Photosynthesis and net assimilation rate showed seasonal and genetic variations among the families. Photosynthetic ability of most of the families except for three families of Pinus rigida decreased with increasing ages, while net assimilation rate of all the families decreased with increasing ages. The rank of photosynthetic ability and net assimilation rate among the families varied during the experimental period. Thus, growth potential was better predicted from total photosynthetic ability and total net assimilation rate rather titan from photosynthetic ability and net assimilation rate at a certain period. Total photosynthetic ability and total net assimilation rate were correlated with total dry weight. Correlation coefficients were 0.6394 and 0.7998, respectively. Thus, growth potential of the two species could be predicted by the measurement of total photosynthetic ability and total net assimilation rate. Family K.G. No. $13{\times}7-107$ from Pinus rigida ${\times}$ P. taeda $F_1$ and family K.G. No. 1 from Pinus rigida were the best in total photosynthetic ability and total net assimilation rate within species.

• Journal of Korean Society of Forest Science
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• v.53 no.1
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• pp.27-36
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• 1981

Foliar nutrient concentrations of N, P, K, Ca, Mg, total sugar, starch, ether extracts were determined for three Pinus spp., that is, P. rigida, P. taeda, P. rigida${\times}$taeda, divided by tree age (16~19-year old, 6-year old), leaf age (current, over-winter, one-year old), planting location(Kyonggi-Do, Chungnam-Do, Junbuk-Do). Foliar compositions of inorganic nutrients were generally put in order of N(0.764~1.502%)>K((0.130~0.491%) $$\geq_-$$Ca(0.165~0.442%)>Mg(0.054~0.121%)${\fallingdotseq}$P(0.041~0.129%) in all the species. The concentrations of total sugar and ether extracts respectively ranged from 5 to 15% of the needles in dry weight base. The concentrations of N, P and K were similarly high in the over-winter needles (sampled in February), but those of Ca were generally high in one-year old needles. As a whole, inorganic nutrient levels in the needles showed different patterns with species, three age, leaf age and location. There were generally positive correlations between nitrogen and phosphorus in foliar concentrations. Foliar concentrations of total sugar showed the ranking of P. rigida > P. rigida${\times}$taeda > P. taeda and the lowest levels in February. Starch in the needles were contained about 10% of total sugar, and the variations of starch level were not regular with the studied factors. Ether extracts contents increased more of less with leaf age but changed irregularly with the other factors.

• The Korean Journal of Mycology
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• v.10 no.3
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• pp.125-129
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• 1982

Of about 70 different mushrooms (potential ectomycorrhizal fungi) collected from forest floor of a 24-year-old Pinus rigida rigida ${\times}$ taeda stand, four species have not been reported in Korea. They are Inocybe fastigiata, Phylloporus bellus, Lactarius glaucescens, and Lactarius subvellereus. The Phylloporus bellus has been incorrectly identified in Korea as Phylloporus rhodoxanthus. Taxonomic descriptions for these four mushrooms are reported in this paper. The collections cited are deposited in the herbarium of Institute of Agricultural science O.R.D.

• Journal of Korean Society of Forest Science
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• v.43 no.1
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• pp.39-50
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• 1979

Twelve Pinus taeda were used as mother trees and one P. rigida plus tree was used as pollen tree for 12 cross combinations. Nine P. densiflora plus trees(4 mother and 7 pollen trees) were used as parents for 11 cross combinations. Those parents and 10 progenies were analyzed for LAP of ${\times}$P. taeda rigida hybrid and P. densiflora and for peroxidase of ${\times}$P. taeda rigida. The analysis, based on the banding patterns, indicate three alleles for LAP-A locus(A1, A2, A3) and two alleles for LAP-B locus (B1, B2) in ${\times}$P. taeda rigida hybrids. Chi-square test on the segregation for progenies did not show significant differences. The results indicated good agreement with monohybrid Mendelian inheritance. Independence test for occurrence frequency of 2 alleles(LAP-A3, LAP-B2) illustrated that there is neither linkage nor repulsion relationship between LAP-A3 and LAP-B2 alleles. Three band at LAP-A locus were always exhibited from all parents and their progenies of P. densiflora. However, the occurrence of two bands at LAP-B locus was variable, one bands assumed as homozygous alleles(B2/B2) and two bands as heterozygous alleles(B1/B2). The segregation ratio for progenies of P. densiflora suggested that LAP-B locus may be controlled by two alleles(B1 and B2). Three Peroxidase loci(Px-A, Px-B, Px-C) assumed to be controlled by allozyme in ${\times}$P. taeda rigida hybrid. The Px-B and Px-C loci could not find out the variations from banding patterns of parents and their progenies, while the Px-A locus showed the variations of occurrence frequency by two bands. The segregation ratio for A1/A2 at LAP-A locus suggest that the peroxidase allozymes of ${\times}$P. taeda rigida hybrid appeare to be monomeric products; that is, Px-A locus may be controlled by two alleles (A1 and A2).