Background Jewel orchid is the common name of several orchid species which can be alike in morphological characteristics, but variable in medicinal properties. At present, two DNA barcode loci, namely, maturase K (matK) and ribulose 1,5-biphosphate carboxylase (rbcL), are intensively utilized for plant identification. However, the discrimination effectiveness of these loci is variable among plant species. This study was carried out to compare the identifying efficacy of these two loci on jewel orchid population collected throughout Vietnam. Results The results revealed that 21 jewel orchid accessions studied were segregated into four different species with significant variations. The discrimination power of matK and rbcL markers in this jewel orchid study displayed different efficiency level. The rbcL gene has higher distinguishing potential than either matK gene alone or the combination of both genes. Conclusion The findings of this project could provide valuable information that is necessary for classification, plant origin identification, breeding, and conservation program of jewel orchid in Vietnam.

The study on the effect of gamma irradiation on in-vitro shoot growth of chrysanthemum cv. Yellow Puma has been carried out. The aim of the study was to observe genetic variability of shoot growth caused by gamma irradiation. Shoot explants with four leaves were irradiated by gamma with dose of 10, 15 and 20 Gy with 3 replications at each of dose. The irradiated shoot explants were then transferred into fresh MS solid medium and placed in a growth room. Observation was performed on number of leaves and branches on M1V0 generation, while plantlets height and number of branches were observed a M1V1 generation. Number of survival plantlets and multiplication rate on three subsequent subcultures were observed as well. Results showed that gamma rays with dose of 20 Gy inhibited growth of leaves as much as 50% compared to control (shoots without irradiation), and branches 73.7% in three weeks. Observation on multiplication rate at M1V1 generation showed that gamma irradiation with dose of 10 Gy promoted multiplication rate as much as 10% higher than control. It can be concluded that in vitro mutagenesis using gamma iradiation with dose of 10 to 15 Gy can be used for inducing genetic variability of chrysanthemum cv. Yellow Puma.

The high lignin content of the seed hull of oilseed rape leads to its black seed color compared to yellow seeded soybean. Reducing lignin and increasing oil and protein content is an important breeding aim in oilseed rape. The objective of the present study was to analyze the inheritance of two rapeseed genetic resources with reduced lignin content in the seeds and to elucidate the effects on seed germination and composition. These resources were crossed to black seeded Express 617 and F1 plants were used to develop two doubled haploid (DH) populations. The two DH populations were tested in field experiments in three to five environments. Significant genetic variation for lignin content and bimodal frequency distributions were found in both populations. SNP marker segregation in contrasting bulks revealed for both populations overlapping narrow genomic regions on chromosome C03, responsible for reduced lignin content. The low lignin bulks had a significantly higher percentage of seeds showing bacterial and fungal growth, but germination and vigor was not affected. Non-targeted metabolome analysis of immature green seeds showed exclusively a depletion of metabolites of the proanthocyanidin pathway in DH lines with a reduced lignin content. In these DH lines, a cinnamate-4-hydroxylase gene copy was identified as candidate gene in the overlapping genomic region of both populations. The newly identified QTL for reduced lignin content on chromosome C03 is valuable for studying additive and epistatic effects in combination with other low lignin genotypes.

No abstract

Grammatophyllum scriptum (L.) Blume atau dikenal sebagai anggrek macan merupakan salah satu anggrek koleksi Kebun Raya Bogor. Jenis ini memiliki perbungaan raksasa dengan ±27 kuntum bunga. Studi ini bertujuan untuk melakukan karakterisasi stomata dan akar dari planlet G. scriptum hasil iradiasi sinar gamma. Dosis iradiasi yang digunakan adalah 0, 15, dan 30 Gray (Gy). Hasil pengamatan menunjukkan iradiasi dengan dosis 15 dan 30 Gy memberikan pengaruh yang signifikan pada kerapatan dan lebar minimum bukaan stomata, namun tidak berpengaruh secara signifikan pada jaringan akar. Planlet dengan dosis 30 Gy memiliki jaringan velamen lebih tipis, stomata dengan kerapatan lebih rendah, celah stomata lebih sempit, dan jumlah stomata rusak lebih banyak, bila dibandingkan dengan planlet dosis iradiasi 15 Gy. Perubahan yang terjadi pada stomata dan akar pada dosis yang berbeda sebagai efek dari iradiasi akan memunculkan cara yang berbeda untuk dapat beradaptasi terhadap lingkungan.