DESKRIPSI KLON TANAMAN UBI KAYU (Manihot esculenta Crantz) YANG DITANAM PETANI DI ENAM KABUPATEN DI PROVINSI LAMPUNG

Penelitian ini dilakukan dengan melakukan pengumpulan data klon ubi kayu dengan melakukan survei di Way Kanan, Lampung Tengah, Lampung Utara, Pringsewu, Tanggamus, dan Metro). Penentuan kabupaten sampel dilakukan dengan metode acak terarah berdasarkan luasan budidaya. Pengambilan sampel desa dilakukan melalui rancangan sampling non-probablitas, yaitu sampling kebetulan (accidental sampling). Data primer diperoleh melalui wawancara kepada petani yang dijumpai di lokasi penelitian meliputi nama lokal, umur tanaman, dan penggunaan klon yang dibudidayaka. Data deskripsi karakteristik morfologis karakteristik vegetatif didapatkan melalui pengamatan langsung di lapangan dengan standarisasi yang ditetapkan oleh International Institute of Tropical Agriculture (IITA) yaitu “Selected Morphological and Agronomic Descriptors for the Characterization of Cassava” oleh Fukuda, dkk. (2010). Ditemukan 15 klon dari 6 kabupaten/kota, di Kabupaten Lampung Tengah ditemui 3 klon ubi kayu (Barokah, Thailand, dan Kasesat), Tanggamus 2 klon (Martapuro dan Baturaja), Pringsewu 2 klon ( Melati dan Pringsewu-1), Way Kanan 3 Klon (S.R. Lowo, Way Kanan -1 dan Way Kanan-2), Kota Metro 2 klon (Manalagi dan Klenteng) dan di Lampung Utara ditemui 3 klon (Roti, Udang, dan Ketan). Analisis klaster dilakukan untuk mengetahui struktur populasi suatu kelompok individu termasuk kemiripan (similarity) atau jarak genetik (distance) dan penyebaran kelompok tertentu dalam populasi dengan menggunakan software SPSS Statistics 23. Terdapat 8 level, klon yang memiliki tingkat kesamaan karakter terbesar adalah klon Martapuro dan S.R Lowo.

The impacts of tropical agriculture on biodiversity: a meta-analysis

Biodiversity underpins all food production and strengthens agricultural resilience to crop failure. However, agricultural expansion is the primary driver of biodiversity loss, particularly in the tropics where crop production is increasing and intensifying rapidly to meet a growing global food demand. It is therefore crucial to ask, how do different crops and crop production systems impact biodiversity? Here we show the increasing intensification of tropical agriculture since 1961, along with a sharp rise in harvested area. Using meta-analysis, we find that crop type, rotation time and agricultural intensity, are important determinants of biodiversity assemblages. Perennial tropical crops that are grown in shaded plantations or agroforests (e.g., banana and coffee) support higher alpha-diversity, while those cultivated in unshaded and often homogeneous plantations (e.g., maize, sugarcane, and oil palm) have impoverished biodiversity communities, particularly annual crops. These findings inform our understanding of changes in the ecological contribution of biodiversity to tropical agriculture.

Sexual dimorphism and the effect of wild introgressions on recombination in cassava (Manihot esculenta Crantz) breeding germplasm

Recombination has essential functions in meiosis, evolution, and breeding. The frequency and distribution of crossovers dictate the generation of new allele combinations and can vary across species and between sexes. Here, we examine recombination landscapes across the 18 chromosomes of cassava (Manihot esculenta Crantz) with respect to male and female meioses and known introgressions from the wild relative Manihot glaziovii. We used SHAPEIT2 and duoHMM to infer crossovers from genotyping-by-sequencing (GBS) data and a validated multi-generational pedigree from the International Institute of Tropical Agriculture (IITA) cassava breeding germplasm consisting of 7,020 informative meioses. We then constructed new genetic maps and compared them to an existing map previously constructed by the International Cassava Genetic Map Consortium (ICGMC). We observed higher recombination rates in females compared to males, and lower recombination rates in M. glaziovii introgression segments on chromosomes 1 and 4, with suppressed recombination along the entire length of the chromosome in the case of the chromosome 4 introgression. Finally, we discuss hypothesized mechanisms underlying our observations of heterochiasmy and crossover suppression and discuss the broader implications for plant breeding.

History and impact of a bean (Phaseolus spp., Leguminosae, Phaseoleae) collection

This work explains the reasons why a bean collection was established in 1973 at the International Center of Tropical Agriculture (CIAT) near Palmira in Colombia. It shows the impact of the collection on plant breeding and in agricultural development through the distribution of germplasm to the center’s bean breeding program, to successively find resistances to pests and diseases, adaptation to low phosphorus and drought, and more recently higher content of iron and zinc in seeds. The collection was also used to progress knowledge in biological sciences, as shown by a dozen of examples. A reason behind these successes was foresight and focus on diversity per se in the collection. The paper ends with a number of suggestions for the way ahead for the genetic resources conservation and management of these bean crops, and possible take-home lessons for curators in charge of other similar collections.

Sexual dimorphism and the effect of wild introgressions on recombination in cassava (Manihot esculenta Crantz) breeding germplasm

Recombination has essential functions in meiosis, evolution, and breeding. The frequency and distribution of crossovers dictate the generation of new allele combinations and can vary across species and between sexes. Here, we examine recombination landscapes across the 18 chromosomes of cassava (Manihot esculenta Crantz) with respect to male and female meioses and known introgressions from the wild relative Manihot glaziovii. We used SHAPEIT2 and duoHMM to infer crossovers from genotyping-by-sequencing (GBS) data and a validated multi-generational pedigree from the International Institute of Tropical Agriculture (IITA) cassava breeding germplasm consisting of 7,020 informative meioses. We then constructed new genetic maps and compared them to an existing map previously constructed by the International Cassava Genetic Map Consortium (ICGMC). We observed higher recombination rates in females compared to males, and lower recombination rates in M. glaziovii introgression segments on chromosomes 1 and 4, with suppressed recombination along the entire length of the chromosome in the case of the chromosome 4 introgression. Finally, we discuss hypothesized mechanisms underlying our observations of heterochiasmy and crossover suppression and discuss the broader implications for plant breeding.

Transition From Targeted Breeding to Mainstreaming of Biofortification Traits in Crop Improvement Programs

Biofortification breeding for three important micronutrients for human health, namely, iron (Fe), zinc (Zn), and provitamin A (PVA), has gained momentum in recent years. HarvestPlus, along with its global consortium partners, enhances Fe, Zn, and PVA in staple crops. The strategic and applied research by HarvestPlus is driven by product-based impact pathway that integrates crop breeding, nutrition research, impact assessment, advocacy, and communication to implement country-specific crop delivery plans. Targeted breeding has resulted in 393 biofortified crop varieties by the end of 2020, which have been released or are in testing in 63 countries, potentially benefitting more than 48 million people. Nevertheless, to reach more than a billion people by 2030, future breeding lines that are being distributed by Consultative Group on International Agricultural Research (CGIAR) centers and submitted by National Agricultural Research System (NARS) to varietal release committees should be biofortified. It is envisaged that the mainstreaming of biofortification traits will be driven by high-throughput micronutrient phenotyping, genomic selection coupled with speed breeding for accelerating genetic gains. It is noteworthy that targeted breeding gradually leads to mainstreaming, as the latter capitalizes on the progress made in the former. Efficacy studies have revealed the nutritional significance of Fe, Zn, and PVA biofortified varieties over non-biofortified ones. Mainstreaming will ensure the integration of biofortified traits into competitive varieties and hybrids developed by private and public sectors. The mainstreaming strategy has just been initiated in select CGIAR centers, namely, International Maize and Wheat Improvement Center (CIMMYT), International Rice Research Institute (IRRI), International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), International Institute of Tropical Agriculture (IITA), and International Center for Tropical Agriculture (CIAT). This review will present the key successes of targeted breeding and its relevance to the mainstreaming approaches to achieve scaling of biofortification to billions sustainably.

Preliminary Study on the Brand Construction of Tropical Agriculture against the Background of We-media—A Case Study of Chinese Academy of Tropical Agricultural Sciences

With the rapid development of electronic industry, "We-media + brand agriculture" model of development also gradually developed, and the tropical agriculture in our country belongs to the "niche" agriculture, awareness is low, in the since the "We-media + brand agriculture" development in our country, is still at a disadvantage, both faces enormous opportunities for development, at the same time to meet the challenge. Taking the Chinese Academy of Tropical Agricultural Sciences as an example, this paper discusses the problems, opportunities and challenges in the brand construction and development of tropical agriculture under the background of "We-media", and puts forward countermeasures and suggestions for the brand development of tropical agriculture.