No abstract

Grain yield of rice is determined by genotype (G), environment (E), and interaction between genotype x environment (G x E). Variety can achieve its maximum yield potential if it is grown in suitable environments. This study was aimed to determine the adaptability and the yield stability of rice genotypes grown in different environments. Sixteen rice genotypes were tested using RBD in 16 sites during the wet season of 2010/2011, and dry season of 2011. The tested rice lines were developed for resistance to pest and diseases. The experiment unit was 4 m x 5 m of plot, plants were fertilized with urea, SP36, and KCl at rates of 250 kg/ha, 100 kg/ha, and 100 kg/ha, respectively. Variable observed was grain yield per plot. Combined analyses of variance showed that there was no lines yielded higher than did check variety Conde. The AMMI analysis showed that the largest variation was contributed by the environment factors (76.49%), genotype x environment interactions (17.55%), and the smallest was contributed by the genotypes (5.97%). Data exploration using boxplot method indicated that the low contribution of the genotype x environment interaction variance in this study was due to the high degree of similarity of yield potentials among the genotypes, and due to high similarity of environmental conditions of the sites.Based on the analysis of AMMI 2, lines B12743 - MR-18-2-3-8, IPB107-F-82-2-1, and Conde was each classified as widely adapted genotypes, while G8, IPB107-F-27-6-1, and BIO111-2-BC-PIR-3714, each was considered as genotype having a specific adaptation.

AvrBs3/PthA Virulence Factor of Bacterial Leaf Blight Race III, Race IV, Race VIII, and IXO93-068. Dwinita W. Utami, Triny S. Kadir, and Siti Yuriyah. Bacterial leaf blight (BLB) is an important disease of rice and present throughout many of the rice-growing regions in the world, also in Indonesia. Xanthomonas oryzae pv. oryzae (Xoo) is the causal agent and a member of the Protebacteria and like many other this phyllum have a type III secretion system for protein virulence effector (PVE) released on their pathogenicity system. Commonly, PVE in Xanthomonas sp., is coded by AvrBs3/PthA family gene. This research was coducted to identify the virulence factor of AvrBs3/PthA on dominant Indonesian BLB isolates (Race III, Race IV, Ras VIII, and IXO93-068). This objective was obtained by sequence analysis through designed markers for members of the virulence factor AvrBs3/PthA gene family (PthXo4, avrXa7#38, PthXoS and avrXa7sacB50). Results gave information that RaceIII is a dependent elicitor race due to no PVE transcript formed and intraceluler protein target with RLL type on NLS (nuclear localization signal). RaceIV and RaceVIII are the virulent race which PVE active formed with intraceluler protein target and have the RLL and RLLP type for the NLS signal. While isolate IXO93-068 is a virulen isolate that active formed a PVE but the extraceluler protein target is due to no type of NLS. Based on cluster analysis, Race VIII has a genetic distance closely to PthXoS and avrXa7sacB50. Keywords

Taro have been cultivated and consumed as a food supplement in Indonesia. Beside it used as a food, it is also as source of industrial purposes, such as a part of raw material of cosmetic or plastic. Characteristic of tuber (corm) of taro determine their usage. Utilization of germplasm collection of taro could be done more intensively by studying their morphological characters. Experiment was conducted in 2005 consisted of 170 accessions of taro. Morphological characters of tuber have been observed at harvest time. Result of the study show that variability of morphological characters were exist within areas or among areas. There are several interesting varieties which have long umbi or high tuber yield and specific tuber flesh color.Key words: Colocasia esculenta, corm, germplasm. ABSTRAKTanaman talas telah lama dibudidayakan dan dimanfaatkan sebagai sumber pangan tambahan di Indonesia. Di samping sebagai sumber pangan, talas juga dapat dimanfaatkan untuk keperluan industri, misalnya sebagai bahan baku kosmetik dan plastik. Karateristik umbi talas menentukan penggunaannya. Pemanfaatan talas dapat ditingkatkan dengan mempelajari sifat-sifat morfologi yang dimiliki plasma nutfah yang telah dikoleksi. Percobaan dilaksanakan pada tahun 2005 terdiri atas 170 aksesi plasma nutfah talas. Karakter morfologi umbi diamati setelah panen. Hasil penelitian menunjukkan bahwa terdapat keragaman karakter morfologi dalam daerah atau antar daerah asal plasma nutfah. Dari koleksi plasma nutfah yang telah dimiliki diperoleh aksesi yang menarik seperti umbi talas yang panjang dengan warna daging umbi yang khas.Kata kunci: Colocasia esculenta, umbi, plasma nutfah.

Studies on cyanogenic potential (CP) of roots and leaves of Indonesian cassava germplasm are still inadequate in relation to food toxicity and on human health. The CP of leaves of 99 cassava cultivars was analyzed using picrate paper kits. Effort to reduce CP of cassava leaves by boiling them was also conducted. The results showed that roots and leaves had low and moderate level of CP. There was a significant correlation between the CP of leaves (Y) and roots (X) of 45 cassava cultivars with regression equation Y = 36.214 + 1.3085 X (r = 0.5228). The CP content was high in the young  leaves (241 ppm) and low in the older ones (99 ppm). The proximal portion of the roots had the highest CP content (300 ppm), and that in the distal end was the lowest (56 ppm). The root part close to cortex had highest CP content (550 ppm), whereas the central part was  the lowest (35 ppm). Boiling cassava leaves for 20 minutes significantly reduced the CP up to 75%, indicating that for safety, cassava should be completely processed or cooked. This study implied that CP content should be considered in cassava breeding programs. Forty two of 99 cassava cultivars have CP below 50 ppm which is safe for consumption.<br /><br />