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One of the most important problems in degraded mined ecosystem is contamination of soil and water by toxic substances, mainly heavy metal such as Pb and others such as cyanide. Phytoremediation could be used as an alternative technique to overcome this problem. Phytoremediation is defined as clean up of pollutans primarily mediated by photosynthetic plants. These plants have several beneficial characteristics such as the ability to accumulate metal in their shoots and an especially high tolerance to heavy metals. This research was carried out to study the potencies of local species to accumulate Pb and cyanide. Seventeen species were collected from mined waste area (namely tailing area) and then the cyanide and Pb accumulated in each species were analyzed. The result showed that some species accumulated Pb and cyanide in high concentration such as Ipomoea sp. (35.70 ppm cyanida) and Mikania cordata (Burm.f.) B.L.Robinson (11.65 ppm Pb). A series of research is needed to prove that these species are potential as heavy metal and cyanide accumulators.

Based on some findings that some plants are tolerant to contaminated media, this research was conducted to study more thoroughly about characters and potencies of some of them as hyperaccumulators. Three of the most tolerant plants were studied in this research i.e Centrocema pubescence, Calopogonium mucunoides,and Micania cordata. The plants were grown in different waste media, i.e. tailing from PT. Aneka Tambang (ANTAM) and people mine waste. Both waste have different characters, physically and chemically. Waste of PT ANTAM major contaminant was cianide (Cn) whereas people mine waste major contaminant was mercury (Hg). This different characters resulted in different plant responses. The plants grown under PT ANTAM waste media gave better performance than that grown under people mine waste media. The most tolerant species was C. pubescence followed by M. cordata and C. mucunoides. Ability in metal accumulation of C. mucunoides was the highest, followed by M. cordata and C. pubescence.The results raised some-prospects for phytoremediation technology for rehabilitating contaminated mined lands.

Some plant species growing in the contaminated areas, indicated high toleranceand potentially affective in accumulating pollutants in their roots and above groundportions. These plants can be utilized as hyperaccumulators for cleaning up thecontaminated sites. Study on heavy metal and CN contamination and potentialplant species for accumulator is urgently needed in order to understand the problemsand to obtain suitable technology for the solution. This research aims to examineCN accumulator plants growing in CN contaminated tailing to find a possible solutionof cleaning up by using green technology of phytoremediation. Phytoremediation isdefined as clean up of pollutants primarily mediated by photosynthetic plants. Thisstudy aims to characterized plants that grow under extreme contaminated media ofgold mined tailing and to analyse their potencies as hyperaccumulators. Mikaniacordata (Burm.f) B.L.Robinson,Centrosema pubescens Bth and Leersia hexandraSwartz which proven tolerant and dominant in the contaminated site were examinedin this research. The plants were grown in tailing waste media added by 0 ppm CN,2.5 ppm CN, 5 ppm CN dan 7.5 ppm CN using complete randomized design with 5replicates. The results showed that the plants were capable of growing under thehighest level of CN. Among three species, Mikania cordata showed the highestbiomass production followed by Centrosema pubescens and Leersia hexandra. TotalCN accumulation varied between species, the highest was reached in 2.5 ppm CNtreatment i.e. 22.48 mg/kg in Leersia hexandra, followed by Centrosema pubescens(18.92 mg/kg) and Mikania cordata (12.03 mg/kg). The highest CN content was0.085 mg in Mikania cordata treated with 7.5 ppm CN. High ratio of shoot to root CN(>1) was expected in hyperaccumulator plants to indicate that CN was more distributedin the above ground portions than in the roots. In this study the highest shoo to rootCN ratio was showed in Mikania cordata i.e.11.75

Understanding drought tolerance status in sorghum (Sorghum bicolor) is very important for the development of sorghum varieties suitable for sub-optimal, drought prone areas in Indonesia. We estimated drought tolerance status of 20 Indonesian sorghum genotypes by observing their leaf water potential under glasshouse condition. Research design was randomized complete block design with 20 sorghum genotypes, 2 water treatments (control and water stress), and 2 replicates. The control plants were irrigated under field capacity, while the water stress treated plants were sown under field capacity followed by drought treatment without watering for one month. Sorghum seeds were cultivated in soil medium containing top soil, organic fertilizer and sand (50:20:30) in four 1x1.2x1 m3 containers. Seeds were sown in soil media pre-treated with tap water under field capacity. Leaf water potential was observed one month after planting by using WP 4 Dew Point. Plant growth performances, including plant height and leaf width were observed. Leaf water potential observation of the 20 sorghum genotypes showed that 2 sorghums genotypes, KLR and KS, had leaf water potential of -2.43 Mpa and - 2.455 Mpa respectively, which were categorized as tolerance to water stress. Four sorghum genotypes, Buleleng Empok, UPCA, Kawali and WHP, had leaf water potential of -3.7275 MPa, -3.7650, - 3.7700 and - 3.7950 Mpa respectively, were classified to be very sensitive to drought stress. The rest of the sorghum genotypes were classified as medium tolerance with leaf water potential between - 2.5200 Mpa and 3.6550 Mpa. Although it is a preliminary results and needs to be combined with field experimental data, the results obtained was an important step in determining sorghum genotypes which was best suited to be cultivated in drought prone areas and also to identify sorghum genotypes suitable to be used as drought tolerant trait donor.