Anthracnose fruit rot is an economically important disease that affects pepper production in Indonesia. Strong resistance to two causal pathogens, Colletotrichum gloeosporioides and C. capsici, was found in an accession of Capsicum chinense. The inheritance of this resistance was studied in an F(2) population derived from a cross of this accession with an Indonesian hot pepper variety ( Capsicum annuum) using a quantitative trait locus (QTL) mapping approach. In laboratory tests where ripe fruits were artificially inoculated with either C. gloeosporioides or C. capsici, three resistance-related traits were scored: the infection frequency, the true lesion diameter (averaged over all lesions that actually developed), and the overall lesion diameter (averaged over all inoculation points, including those that did not develop lesions). One main QTL was identified with highly significant and large effects on all three traits after inoculation with C. gloeosporioides and on true lesion diameter after inoculation with C. capsici. Three other QTL with smaller effects were found for overall lesion diameter and true lesion diameter after inoculation with C. gloeosporioides, two of which also had an effect on infection frequency. Interestingly, the resistant parent carried a susceptible allele for a QTL for all three traits that was closely linked to the main QTL. The results with C. capsici were based on less observations and therefore less informative. Although the main QTL was shown to have an effect on true lesion diameter after inoculation with C. capsici, no significant QTL were identified for overall lesion diameter or infection frequency.

Cultivation of chrysanthemum at low elevation was one effort to expand potential production areas. Under these circumstances, several environmental conditions might not be as conducive as in highland and deviate the plant from the original characters and potential yield. Fifteen promising variants derived from an unconventional breeding program were evaluated at two different elevations; 1100 and 250 m above sea level (asl) at Cianjur-West Java, Indonesia during hot season from April to September 2016. The experiment was designed as progenital selection to seek the adaptive genotypes on the targeted sites. The results showed that varietal differences existed among the tested clones when grown under highland and lowland. At lowland (250 m asl), all clones showed growth retardation expressed by the reduction of flower qualities with different degrees among genotypes. In standard group, only 2015-9 and 2015-15 that produced unchanged flower color, with acceptable plant height standard for cut flower. While in spray type, all tested clones produced flower with degraded floret color.

ABSTRAKTeknik konservasi in vitro telah dikembangkan untuk pelestarian sumber daya genetik krisan. Penelitian ini dilakukan dengan tujuan mengevaluasi beberapa komposisi media yang terbaik untuk konservasi in vitro krisan. Penelitian dilakukan di Laboratorium Kultur Jaringan di Balai Penelitian Tanaman Hias dari bulan Juni 2014 hingga Oktober 2016. Penelitian ini menggunakan Rancangan Acak Lengkap Faktorial dengan tiga ulangan. Kombinasi perlakuan adalah tiga varietas krisan dan tujuh formulasi media yang disimpan pada dua kondisi penyimpanan planlet, yaitu suhu rendah dan kondisi ruang. Hasil penelitian menunjukkan bahwa planlet yang berada pada media ½ MS + sukrosa 6% mempunyai persentase planlet hidup yang tinggi dibanding media lain pada 4, 7, dan 9 bulan penyimpanan. Kondisi lingkungan penyimpanan bersuhu rendah memberikan persentase planlet hidup dengan penurunan kematian lebih rendah setelah sembilan bulan. Pada kondisi ini, persentase planlet hidup berkisar antara 51,3-66,3%. Varietas krisan Monalisa menunjukkan ketahanan planlet lebih tinggi dibanding varietas Merahayani dan Town Talk.Kata kunci: Krisan, evaluasi media, konservasi in vitro, persentase planlet hidup, kematian planlet. ABSTRACTIn vitro technique for conservation of genetic resources of chrysanthemum was developed through the application of selected medium under different storage conditions. The research was conducted from June 2014 to October 2016. The experiment was conducted in a completely randomized design which consisted of three chrysanthemum varieties and seven medium formulations and maintained in two storage conditions, i.e. low-temperature and ambient room conditions. The results showed that plantlet of all varieties conserved under ½ MS + 6% sucrose had higher survivals and slighter death rates after 4, 7, and 9 months. Lowtemperature condition provided more suitable circumstances for the respected medium to preserve the plantlet life during 9 months of in vitro storage. Under these conditions, the plantlet survivals ranged 51.3-66.3%. While among the chrysanthemum varieties, Monalisa had highest plantlet survivals than Merahayani and Town Talk.

Hama Thrips parvispinus merupakan salah satu faktor pembatas dalam sistem produksi bunga krisan. Penggunaan tanaman genotipe tahan merupakan salah satu upaya pengendalian hama T. parvispinus pada krisan yang ramah lingkungan. Penelitian ini bertujuan mengetahui ketahanan beberapa genotipe krisan mutan Balai Penelitian Tanaman Hias (BALITHI) terhadap hama spesies T. parvispinus. Penelitian dilaksanakan di rumah lindung Instalasi Penelitian dan Pengkajian Teknologi Pertanian (IP2TP) BALITHI Segunung dari bulan Januari sampai Desember 2019. Sebanyak 10 genotipe krisan mutan BALITHI dan 2 genotipe introduksi (Fiji Kuning dan Fiji Putih) digunakan dalam penelitian dengan Rancangan Acak Kelompok 3 tiga ulangan.  Metode skrining menggunakan hama T. parvispinus. yang ada di alam atau tanpa investasi. Variabel pengamatan meliputi intensitas serangan hama, persentase serangan hama, persentase bunga layak panen, dan diameter bunga. Hasil penelitian menunjukkan krisan mutan BALITHI Mayang Ratih agak tahan terhadap hama Thrips ini dengan rata-rata intensitas dan persentase serangan hama paling rendah serta bunga layak panen tertinggi serta diameter bunga memenuhi syarat sebagai bunga krisan potong tipe standar. Genotipe Mayang Ratih selanjutnya dapat direkomendasikan sebagai tetua tahan T. parvispinus. untuk program pemuliaan bunga potong krisan.   Kata kunci: bunga, Dendrathema grandiflora, hama, intensitas serangan