Screening of Vietnamese soybean genotypes for Agrobacterium-mediated transgenic transformation

Soybean [Glycine max (L) Merr.] is one of the most important crops used for human food and animal feed globally. Transgenic soybean covers more than 74% of the global soybean production area, which is an achievement of genetically modified programs. The Agrobacterium-mediated method is commonly used for soybean transformation, but the efficiency of this method is affected by various factors including genotypes. Screening of the soybean genotypes suitable for Agrobacterium-infection and plant regeneration is the most important step to establish an efficient genetic transformation system. In this study, we screened thirty Vietnamese soybean genotypes including seventeen cultivated soybean genotypes (CSG) and thirteen local soybean genotypes (LCG) for shoot regeneration ability and transient infection via Agrobacterium tumefaciens method. Two CSG cultivars, DT22 and VX93, had significantly high efficiencies for shoot regeneration and transient infection compared with the control genotypes Jack and William 82. The shoot regeneration of DT22 and VX93 was 92.32% with 5.75 shoots/explant and 93.35% with 5.92 shoots/explant, respectively, whereas the control genotypes Jack and William 82 had 91.35% with 4.6 shoots/explant and 82.64% with 5.7 shoots/explant. Similarly, the transient infection of DT22 and VX93 was 84% and 86%, respectively, which was comparable with that of Jack (86%) William (82%). The success of transgenic development was confirmed by the β-Glucuronidase staining, PCR, and Basta leaf painting. The results indicated that cultivars DT22 and VX93 could be used for stable Agrobacterium-media transformation. Keywords: Soybean, Agrobacterium, transformation, transient infection, transgenic.

Evaluation of biogas production from manure of hybrid and local breed cows fed with different types of feeding practices

This study aimed to evaluate the biogas production from the manure of hybrid and local breed cows fed with different types of feeding practices. The feedstock and digestive composition were measured to determine their effects on biogas production. The batches were prepared form manure of hybrid and local breed cows fed with roughages and mixed ration (roughages and concentrate) adding Inoculum (I) and with a total weight of 200 g. Four experimental groups (T1, T2, T3 and T4) were set up using mixing ratios of CM: H2O: I (25: 25: 50). The digesters were set up at ambient temperature for 40 days of Hydraulic Retention Time (HRT) using a water displacement method to monitor biogas production in the proto-type digesters. The biogas yield from the manure was found 250.90 Nml/g VS for T1, 176.50 Nml/g VS for T2, 208.25 Nml/g VS for T3 and 180.88 Nml/g VS for T4, respectively. The average CH4 and CO2 concentration (% vol.) in biogas were found 53% and 47% for T1, 55% and 45% for T2, 52% and 48% for T3, 53% and 47% for T4, respectively. The content of H2S was not found in this study. The study concluded that the overall biogas production was higher in the manure of hybrid cows fed with roughages. However, the biogas production was also higher in the manure of local breed cows fed with roughages than mixed ration. The results indicated that C, N, P, K and S values were relatively lower in this study. Keywords: Biogas, CH4, hybrid and local breed cows, prototype digester, HRT.

Effect of growing media on the germination and seedling growth of Borneo sour eggplant

Borneo sour eggplant, a popular indigenous fruit vegetable in Borneo, has become an important fruit not only to local people, but also to tourists who visit Borneo. One of the challenges in planting this crop is lacking information, particularly in finding suitable media for its growth, eventually inhibiting local farmers from growing the crop commercially. This study was conducted to investigate the effects of 4 growing media compositions (M1: topsoil, M2: topsoil and compost, M3: topsoil and cocopeat and M4: topsoil, compost and cocopeat) on the germination and growth performance of sour eggplant seedlings. The experiment was tested in a randomized complete block design (RCBD) with 10 replicates. At the end of germination period, seeds planted in M4 medium produced the highest germination rate of 96.67% and was significantly different (P < 0.05) from those sown in other growing media. However, the performance of the seedlings in terms of height, stem diameter, number of leaves and length of leaves showed significant increase (P < 0.05) in M2 medium. This study has demonstrated that M2 medium could improve the growth performance of the seedlings and therefore is recommended as suitable growing media for planting sour eggplant. Keywords: Growth performance, growing medium, indigenous fruit, sour eggplant.