Induksi dan Proliferasi Kalus Embriogenik pada Beberapa Genotipe Kedelai

The successful of gene transformation on crop plants depends on the ability of explant to develop somatic embryos. The effect of medium composition on induction and proliferation of embryonic callus was analyzed on several soybean genotypes, including low irradiance (LI) tolerant genotype (Ceneng, Pangrango C6-30-10 and C6-76-10) and two LI sensitive genotypes (Godeg and Slamet). Immature cotyledons (14 DAA) were cultured in induction medium including MSIA (MS, vitamin B5, 30% sucrose, 0.2% gelrite, 10 mg L-1 2,4-D and 10 mg L-1 NAA) and MSIB (MS, vitamin B5, 30% sucrose, 0.2% gelrite, and 40 mg L-1 2,4-D). Embryonic calli was subcultered one month after initiation onto proliferation medium including MSIIA (MS, vit. B5, 30% sucrose, 0.2% gelrite, 5 mg L-1 2,4-D and 5 mg L-1 NAA) and MSIIB (MS, vitamin B5, 30% sucrose, 0.2% gelrite, and 20 mg L-1 2,4-D). The result showed that percentage of callused explant was 76-94% and the highest initiation obtained on Pangrango genotypes. The average of calli diameter at 1 month after initiation was 0.5-1.2 cm. Calli which was obtained on MSIA medium showed yellow, tranparent, and friable, whereas calli was obtained on MSIB medium showed yellow-brown, transparent, and friable. Increasing calli diameter and structure were obtained on proliferation medium. The combination of 2,4-D and NAA on MSIA and MSIIA both are induction and proliferation medium respectively were better than MSIB and MSIIB which were contain only 2,4-D. Ceneng genotype showed best performance of somatic embryogenesis than others, and Slamet genotype showed lowest response both on callus induction and proliferation

Respon Anatomi dan Fisiologi Akar Kedelai terhadap Cekaman Kekeringan

Drought stress in crop occurs due to imbalance between demand and supply of water. Crop responses to drought stress depend on their genotypes. Drought stress causes anatomical changes and root damage. The objective of this research was to study the effect of drought stress on anatomy and physiology of soybean root. The research was conducted at Laboratory of Microtechnique, Department of Agronomy and Horticulture, Bogor Agricultural University in November 2013. A Completely Randomized Design with two factors was used in the research i.e. soybean genotypes (Wilis, PG 57-1, SC 39-1) and PEG (0, 20%) with three replications. The result showed that genotype and PEG affected the size of the cortex, stele, and xylem. PG 57-1 genotype showed the decrease of cortical thickness, diameter of stele and the diameter of xylem, on the other hand, in SC 39-1, there was an increase. Drought stress (PEG 20%) could also cause damage to the root membrane as indicated by the occurrence of lipid peroxides. Wilis and PG 57-1 were tolerant while SC 39-1 was sensitive to drought stress

Keragaman Beberapa Aksesi Temu Hitam (Curcuma Aeruginosa Roxb.) Berdasarkan Karakter Morfologi

Curcuma aeruginosa Roxb. or black turmeric belongs to the family Zingiberaceae is one of the important medicinal plant that is widely distributed in Southeast Asia, including in Indonesia. This plant has been used by the people especially as raw material for medicine and cosmetics industries. However, the development of black turmeric is still constrained by the availability of germplasm collection and improved varieties. The objective of this study was to determine the vegetative morphological characters and phylogenetic relationship among 10 accessions of black turmeric and 3 accessions of genus Curcuma in Indonesia. Data was collected for 15 morphological quantitative characters of black turmeric at the Experimental Garden at Sukamantri IPB based on UPOV and PPVFRA descriptors. The result of principal component analysis has determined three principal components with the proportion of diversity 73.94%. Cluster analysis three clusters accession of black turmeric, namely cluster 1 consisted of accession Cianjur, Malang, Rimbo, and Kendal; cluster 2 consisted of accession Bogor, turmeric (Curcuma longa L.), java turmeric (Curcuma xanthorrhiza Roxb.), Liwa, Natar, white turmeric (Curcuma zedoaria Roscoe.); cluster 3 consisted of accession Cirebon, Kuningan 1, and Kuningan 2

Radiosensitivitas dan Heritabilitas Ketahanan terhadap Penyakit Antraknosa pada Tiga Populasi Cabai yang Diinduksi Iradiasi Sinar Gamma

Commercial varieties of Chili is still susceptible to anthracnose disease. Anthracnose is one of diseases which caused yield loss about 10-80% in rainy season and 2-35% in dry season. One of the disease control method is to develop new varieties resistant to anthracnose through gamma-ray irradiation. This research was aimed to determine radiosensitivity level and heritability of Chili which generated by mutation inductions of three genotypes: IPB C2, IPB C10, and IPB C15. Seed of the three genotypes were irradiated by gamma rays at dosages of 100, 200, 300, 400, 500, 600, 700, 800, 900 and 1,000 Gy. The LD50 in IPB C2, IPB C10, and IPB C15 were 317.9, 591.4, and 538.8 Gy, respectively. The character of IPB C2 mutants ranged between very susceptible to resistant against anthracnose disease, IPB C10 tended to very susceptible to highly resistant, and genotype IPB C15 tended to susceptible to highly resistant. Genotype IPB C2 had high level in heritability for disease resistance character, while medium level in heritability value was obtained on genotype IPB C10 and IPB C15.Keywords: genotype, LD50, mutant, mutation, see

Somaclonal Putative Mutants of Rice Tolerant to Salinity

Soil salinity could significantly reduce rice yield, therefore, varieties tolerant to salinity are urgent to be developed. Mutation induction could be used to create rice mutants tolerant to salinity. The study aimed to evaluate the tolerance of somaclonal mutants of rice to NaCl salinity in a greenhouse condition and characterize their tolerance mechanism. A total of 45 putative mutants were generated by a gamma ray mutation induction followed with in vitro selection in the growth media containing different NaCl concentrations in the greenhouse experiment. The study consisted of two-factor treatments, namely three levels of NaCl concentrations and 45 rice mutants suspected to be tolerant to salinity, arranged in a completely randomized design. Proline, cations (K, Na, Ca, and Mg) content, and stomata density were evaluated. The results showed that eight mutants were tolerant to 150 mM NaCl, namely CH30, CH-4-2, II-13-42, II-13-7, II-13-10, II-13-13, II-13- 2, and IA-3-21. These tolerant mutants had a higher Na content compared to the check parent. The tolerant mutants had a high proline content, lower Na, and stable K, Mg and Ca cations as well as had a greater number of stomata and higher stomata length-width ratio. Some of the identified tolerant mutants demonstrated the tolerant mechanism against salinity stress. Further studies are required to evaluate these tolerant mutants in the field conditions under salinity stress

Toleransi Beberapa Genotipe Gandum (Triticum Aestivum L.) terhadap Kekeringan pada Stadia Perkecambahan

Drought is a major abiotic stress impeding wheat production world wide. Selection of potentially drought tolerant genotypes are necessary for wheat improvement. The objective of this study was to test the tolerance level of nine wheat genotypes to drought stress at germination stage. Assesment at germination stage using osmoticum solution is an effective method for selecting tolerant genotypes to drougt stress in a short period of time. The experiment was arranged on a randomized complete block design with two factors and three replications. The first factor was wheat genotype consisted of Nias, Selayar, Dewata, H-20, Munal, SBD, SBR, S-03, and YMH. The second factor was concentration of PEG 6000 consisted of 0, 5, 10, 15, and 20%. Observation variables were germination percentage, shoot length, root length, number of root, number of leaf, seedling fresh weight, and seedling dry weight. Increasing level of PEG concentration inhibited the growth of wheat seedling. Based on the highes R2 value on the regression analysis, relative root length can be used as selection character. Based on RD50 value of relative root length, 15% PEG was determined concentration to select drought tolerant on wheat genotypes. Nias genotype was identified as tolerant genotype, while SBD, S-03, YMH, and Munal were identified as drought sensitive genotypes