Iswari S. Dewi

Pemanfaatan Teknik Kultur In Vitro untuk Konservasi Plasma Nutfah Ubi-ubian

Except for potato, sweet potato, taro, yam, and cassava, most of tuber crops are considered as underutilized crops. However, tuber crops are potential as alternative carbohydrate sources, so they can be used as food reserves to face global climate change that affects food security in certain area throughout the world, including Indonesia. Having high diversity in tuber crops germplasm, Indonesia must be able to conserve those germplasm to ensure their availability in the future. In the future, without ignoring all the probable constraints, the prospect in utilization of in vitro culture technique will be higher for improvement of conservation and management of genetic resources in the form of active and base collections. In this paper, strategy in developing in vitro collection of tuber crops germplasm, i.e. slow growth technique for medium term storage and cryopreservation technique for long term storage, is discussed including how to analyze genetic stability of the collections. Several national and international research centers dealing with research and development of in vitro conservation technique are presented.

Induksi Mutasi dan Keragaman Somaklonal untuk Meningkatkan Ketahanan Penyakit Blas Daun pada Padi Fatmawati

In Vitro Culture Application in the form of Somaclonal Variation Combined with Mutagen Introduction for Plant Improvement. Fatmawati is a new type of rice potentially to be developed. The development of this new type of rice in various places of West Java, Central Java and Lampung is often hampered by the blast disease causing the empty grain resulted in the harvest failure. Hence, from January to December 2007. The Indonesia Research Institute for rice in cooperation with Indonesian Center for Agricultural Biotechnology and Genetic Resources Research and Development conducted research aimed at improving the quality of Fatmawati type of rice through somaclonal variation by mutative induction. In this research, the calli were treated with 1-50 gy gamma ray prior to its regeneration. The shoots produced by this regeneration were then acclimatized in the green house until the production stage. All 342 somaclone lines were sub-sequently tested on its endurance against leaf blast disease using three races of blast isolate namely 001, 033, and 173. The research yielded 21 somaclone lines which were absolutely tolerant to blast disease. These new somaclones were then planted in the green house for further morphological and agronomical observation. Abstrak Fatmawati merupakan varietas padi tipe baru yang mempunyai potensi hasil tinggi. Pengembangan varietas tersebut di beberapa daerah seperti Jawa Barat, Jawa Tengah, dan Lampung masih mengalami masalah berupa bulir hampa tinggi dan serangan penyakit blas yang menyebabkan kegagalan panen. Penelitian pemuliaan untuk memperbaiki sifat unggul pada varietas Fatmawati telah dilakukan oleh Balai Besar Penelitian Padi bekerjasama dengan Balai Besar Penelitian dan Pengembangan Bioteknologi dan Sumberdaya Genetik Pertanian melalui keragaman somaklonal menggunakan induksi mutasi. Penelitian dilakukan pada bulan Januari-Desember 2007. Bahan tanaman yang digunakan adalah kalus yang diberi perlakuan irradiasi dengan sinar gamma dosis 1-50 Gy kemudian diregenerasikan pada media MS + BA 1 mg/l +IAA 0,8 mg/l. Tunas yang dihasilkan kemudian diaklimatisasi di rumah kaca sampai menghasilkan benih. Sebanyak 342 galur somaklon diuji ketahanannya terhadap penyakit blas daun menggunakan ras isolat 001, 033, dan 173. Hasil penelitian menghasilkan 21 galur somaklon yang sama sekali tidak terserang penyakit blas. Galur somaklon tahan tersebut selanjutnya ditanam di rumah kaca untuk diamati keragaman morfologi dan agronominya.

Seleksi Galur Mutan Padi Fatmawati Tahan terhadap Penyakit Blas dan Evaluasi Karakter Agronomi di Rumah Kaca dan di Lahan Sawah

Fatmawati, a rice variety released in 2003, is a new plant type (NPT) of rice that had different characteristic from existing high yielding rice varieties (HYV). The yield potential of this rice variety is 7.5 t/ha. Therefore its cultivated is expected to increase national rice production. However, the dissemination of this variety was hampered in several regions due to its susceptibility to blast disease and high percentage of empty grain caused by partially exserted and enclosed panicle. This research was conducted to evaluate 104 dihaploid mutant lines of Fatmawati for resistance to blast disease and good agronomic characters, especially for panicle exsertion rate. The first research was conducted in the endemic area of blast disease at Cikembar-Sukabumi, West Java. The blast disease resistance lines were then subsequently evaluated for their agronomic characters by planting in the green house and in the field. The results indicated that 40 dihaploid mutant lines were characterized as resistant and moderately resistant to blast (score 3n5). Agronomic characters evaluation in the green house and in the field resulted in 11 dihaploid mutant lines with well exerted panicle (0% of coverage of panicle by flagleaf sheath) and high grains per panicle (229n283 grains/panicle). Those lines were F99, F102, F116, F122, F130, F134, F138, F147, F149, F150, and F153. Abstrak Fatmawati, varietas padi yang dilepas tahun 2003, adalah padi tipe baru (PTB) yang mempunyai karakteristik berbeda dari varietas padi unggul baru (VUB). Potensi hasil varietas padi ini adalah 7,5 t/ha. Penanaman varietas ini diharapkan akan meningkatkan produksi padi nasional. Namun, diseminasi varietas ini di beberapa tempat mengalami hambatan karena kerentanannya terhadap penyakit blas dan tingginya persentase gabah hampa akibat setengah tertutupnya atau tertutup semuanya malai oleh pelepah daun bendera. Penelitian ini dilakukan untuk mengevaluasi 104 galur mutan dihaploid turunan Fatmawati terhadap ketahanan blas dan karakter agronomi, khususnya laju keluarnya malai. Penelitian pertama dilakukan di daerah endemik penyakit blas di Cikembar- Sukabumi, Jawa Barat. Galur-galur yang tahan blas kemudian dievaluasi karakter agronominya dengan menanam di rumah kaca dan lapang. Hasil penelitian menunjukkan terdapat 40 galur mutan dihaploid dikategorikan sebagai tahan dan agak tahan penyakit blas (skor 3n5). Evaluasi karakter agronomi di rumah kaca dan lapang menghasilkan 11 galur mutan dihaploid yang malainya sempurna keluar (0% penutupan malai oleh pelepah daun bendera) dan jumlah gabah/malai tinggi (229n283 gabah/malai). Galur mutan dihaploid tersebut adalah galur F99, F102, F116, F122, F130, F134, F138, F147, F149, F150, dan F153.

Penampilan Galur Harapan Mutan Dihaploid Padi Tipe Baru di Sulawesi Selatan

ABSTRACT South Sulawesi is known as one of national rice production centers. However, average productivity of rice varieties planted in that area (4.43 ton ha-1) is lower than those of rice productivity in Java (5.25 ton ha-1). The aims of this research were to evaluate agronomic characters and adaptation of 7 dihaploid mutant advanced lines of new plant type (DH-NPT) of rice at several locations in South Sulawesi. The research was conducted in 2012 at Maros, Gowa, Barru, and Pangkep. The experiments were conducted in randomized complete block design with 3 replications nested in locations. Treatment consisted of 7 DH-NPT of rice, i.e., BIO-MF115, BIO-MF116, BIO-MF125, BIO-MF130, BIO-MF133, BIO-MF151, BIO-MF153, and control varieties i.e., Fatmawati, Ciherang, and Inpari13. The results indicated that in general the lines had medium height (102.77-110.23 cm), moderate productive tiller (9-16 tiller per hill), moderate days to flower (50%), i.e., 73-76 days after sowing (DAS), earlier days to harvest (103-110 DAS), moderate panicle length (28.35-29.31 cm), large number of grain per panicle (> 250 grains) with moderate panicle fertility (63-70%), moderate 1,000 grain weight, i.e., 26.51-27.75 g, and high yield (7.51-8.09 ton ha-1). Four lines, i.e., BIO-MF116, BIO-MF130, BIO-MF151, and BIO-MF153 were stable and had wide adaptability. Other lines, i.e., BIO-MF125 and BIO-MF133 were sensitive to environmental changes, therefore they were classified as specifically adapted to favorable environment; while BIO-MF115 was not sensitive to environmental changes, and therefore it was adapted to non-favorable environment. Keywords: adaptation, agronomic characters, rice mutant

Morfologi Bunga dan Korelasinya terhadap Kemampuan Menyerbuk Silang Galur Mandul Jantan Padi

Good male sterile lines should have high and stable sterility, as well as have good characters of flowers that enhances the outcrossing ability. Research was conducted at Sukamandi field station during DS of 2010 to study the character and flowering behaviour and their genetic variability among the new CMS lines. Five new CMS lines were tested in the field in three replicates of randomized complete block design. The results showed that CMS derived from the Wild Abortive, Kalinga and Gambiaca all were early flowering. The new CMS lines have better flower characters than that of IR58025A, including the following: bigger stigma, higher stigma exsertion percentage, wider degree of glume opening, and longer duration of glume opening. Better flowering behaviour enhanced the ability of outcrossing, and resulted in seed set obtained from CMS lines, up to 25.90%; the traditional IR58025A CMS line produced seed set of only 2.98%. The significant positive correlation was found between seed set with stigma width (r = 0.44*), with stigma exsertion (r = 0.54*); and with degree of glume opening of male sterile lines (r = 0.42*); also with filament length (r = 0.47*) and degree of glume opening of maintainer line (r = 0.57**). Those characters are important for the seed set of CMS lines in the hybrid seed production.