Genetic Diversity of 64 Turmeric Accessions from Indonesia Based on P450-Based Analogue (PBA) Marker

Kunyit merupakan tanaman penghasil rimpang yang memiliki banyak kegunaan, baik untuk konsumsi, industri obat, maupun pewarna. Pengembangan varietas unggul kunyit di Indonesia saat ini perlu didukung oleh adanya informasi keragaman genetik. Saat ini informasi mengenai keragaman genetik tanaman kunyit di Indonesia masih belum tersedia. Salah satu cara untuk memperoleh informasi keragaman genetik adalah dengan menggunakan marka molekuler yang mampu memberikan hasil yang akurat dan tidak dipengaruhi oleh lingkungan. Marka PBA sebagai marka fungsional mampu mendeteksi gen P450 yang berkaitan dengan pembentukan metabolit sekunder pada area genom yang luas sehingga dapat dijadikan alternatif marka untuk mengidentifikasi keragaman genetik. Tujuan dari penelitian ini adalah untuk memperoleh informasi keragaman genetik 64 aksesi tanaman kunyit menggunakan delapan pasang primer P450-Based Analogue (PBA). Penelitian dilakukan di Laboratorium Sentral Universitas Padjadjaran dari Juni 2019 hingga Januari 2020. Sebanyak 133 pita terdeteksi dengan rentang jumlah masing-masing alel 8 – 45 pita, dan rata-rata per alel 22,3 pita. Hasil analisis PIC menunjukkan adanya enam pasang primer PBA yang menunjukkan polimorfisme tinggi pada rentang 0,90 – 0,98 sehingga marka PBA dikategorikan sangat informatif. Analisis klaster membagi 64 aksesi kunyit ke dalam dua klaster utama berdasarkan tingkat kemiripan pada rentang 0,01 hingga 0,83. Aksesi CL-GTL01 yang berasal dari Gorontalo memiliki kemiripan yang rendah yaitu 0,01 terhadap 64 aksesi lainnya, sedangkan aksesi CL-NTB01 dan CL-PPB04 memiliki tingkat kemiripan yang tinggi pada jarak 0,83. Berdasarkan nilai PIC, jumlah pita polimorfik, dan jarak genetik, kunyit asal Indonesia memiliki keragaman yang luas berdasarkan marka PBA. Turmeric is a rhizome producing plant with many utilization such as for consumption, medicine, and colorant industries. The development of superior turmeric varieties in Indonesia needs to be supported by genetic diversity information availability. Despite its potential, genetic diversity information of Indonesian turmeric has not been widely observed. A molecular marker is used to address genetic diversity information with the accurate result due to minimum environmental influences. PBA can detect the P450 gene as a functional marker, which is related to the synthesis of secondary metabolites in a wide genome area.  Thus, it can be used as an alternative marker to identify genetic diversity. This research aimed to obtain genetic diversity information of 64 turmeric accessions using eight primer sets of P450-Based Analogue (PBA). The study was conducted in the Central Laboratory of Padjadjaran University from June 2019 to January 2020. Results showed that the full 133 bands were detected with a range of allele number 8 - 45 bands and an average of 22.3 bands per allele. PIC analysis showed six primer sets of PBA had high polymorphisms ranged from 0.90 to 0.98, hence categorized PBA as a highly informative marker. Cluster analysis divided 64 turmeric accessions into two main clusters based on a similarity index ranged from 0.01 to 0.83. The accession of CL-GTL01 origins from Gorontalo had a low similarity coefficient of 0.01 to the other 64 accessions cluster. On the other hand, CL-NTB01 dan CL-PPB01 had the highest similarity index of 0.83. Based on the PIC value, the total number of polymorphic bands, and genetic distance, it can be concluded that local Indonesian turmeric had wide diversity based on PBA marker

Pathotype Diversity of Phytophthora sojae in Eleven States in the United States

Pathotype diversity of Phytophthora sojae was assessed in 11 states in the United States during 2012 and 2013. Isolates of P. sojae were recovered from 202 fields, either from soil samples using a soybean seedling bioassay or by isolation from symptomatic plants. Each isolate was inoculated directly onto 12 soybean differentials; no Rps gene or Rps 1a, 1b, 1c, 1k, 3a, 3b, 3c, 4, 6, 7, or 8. There were 213 unique virulence pathotypes identified among the 873 isolates collected. None of the Rps genes were effective against all the isolates collected but Rps6 and Rps8 were effective against the majority of isolates collected in the northern regions of the sampled area. Virulence toward Rps1a, 1b, 1c, and 1k ranged from 36 to 100% of isolates collected in each state, while virulence to Rps6 and Rps8 was less than 36 and 10%, respectively. Depending on the state, the effectiveness of Rps3a ranged from totally effective to susceptible to more than 40% of the isolates. Pathotype complexity has increased in populations of P. sojae in the United States, emphasizing the increasing importance of stacked Rps genes in combination with high partial resistance as a means of limiting losses to P. sojae

Unused Natural Variation Can Lift Yield Barriers in Plant Breeding

Natural biodiversity is an underexploited sustainable resource that can enrich the genetic basis of cultivated plants with novel alleles that improve productivity and adaptation. We evaluated the progress in breeding for increased tomato (Solanum lycopersicum) yield using genotypes carrying a pyramid of three independent yield-promoting genomic regions introduced from the drought-tolerant green-fruited wild species Solanum pennellii. Yield of hybrids parented by the pyramided genotypes was more than 50% higher than that of a control market leader variety under both wet and dry field conditions that received 10% of the irrigation water. This demonstration of the breaking of agricultural yield barriers provides the rationale for implementing similar strategies for other agricultural organisms that are important for global food security

Geographic Distribution of Soybean Aphid Biotypes in the United States and Canada during 2008–2010

Soybean aphid (Aphis glycines Matsumura) is a native pest of soybean [Glycine max (L.) Merr.] in eastern Asia and was detected on soybeans in North America in 2000. In 2004, the soybean cultivar Dowling was described to be resistant to soybean aphids with the Rag1 gene for resistance. In 2006, a virulent biotype of soybean aphid in Ohio was reported to proliferate on soybeans with the Rag1 gene. The objective was to survey the occurrence of virulent aphid populations on soybean indicator lines across geographies and years. Nine soybean lines were identified on the basis of their degree of aphid resistance and their importance in breeding programs. Naturally occurring soybean aphid populations were collected in 10 states (Kansas, Illinois, Indiana, Iowa, Michigan, Minnesota, North Dakota, Ohio, South Dakota, and Wisconsin) and the Canadian province of Ontario. The reproductive capacity of field-collected soybean aphid populations was tested on soybean lines; growth rates were compared in no-choice field cages at each geographic region across 3 yr. The occurrence of soybean aphid biotypes was highly variable from year to year and across environments. The frequency of Biotypes 2, 3, and 4 was 54, 18, and 7%, respectively, from the 28 soybean aphid populations collected across 3 yr and 11 environments. Plant introduction (PI) 567598B, a natural gene pyramid of rag1c and rag4, had lowest frequency of soybean aphid colonization (18%). Several factors may have contributed to the variability, including genetic diversity of soybean aphids, parthenogenicity, abundance of the overwintering host buckthorn (Rhamnus spp.), and migratory patterns of soybean aphids across the landscape

A High Density Integrated Genetic Linkage Map of Soybean and the Development of a 1536 Universal Soy Linkage Panel for Quantitative Trait Locus Mapping

Single nucleotide polymorphisms (SNPs) are the marker of choice for many researchers due to their abundance and the high-throughput methods available for their multiplex analysis. Only recently have SNP markers been available to researchers in soybean [Glycine max (L.) Merr.] with the release of the third version of the consensus genetic linkage map that added 1141 SNP markers to the map. Our objectives were to add 2500 additional SNP markers to the soybean integrated map and select a set of 1536 SNPs to create a universal linkage panel for high-throughput soybean quantitative trait locus (QTL) mapping. The GoldenGate assay is one high-throughput analysis method capable of genotyping 1536 SNPs in 192 DNA samples over a 3-d period. We designed GoldenGate assays for 3456 SNPs (2956 new plus 500 previously mapped) which were used to screen three recombinant inbred line populations and diverse germplasm. A total of 3000 workable assays were obtained which added about 2500 new SNP markers to create a fourth version of the soybean integrated linkage map. To create a “Universal Soy Linkage Panel” (USLP 1.0) of 1536 SNP loci, SNPs were selected based on even distribution throughout each of the 20 consensus linkage groups and to have a broad range of allele frequencies in diverse germplasm. The 1536 USLP 1.0 will be able to quickly create a comprehensive genetic map in most QTL mapping populations and thus will serve as a useful tool for high-throughput QTL mapping