Effects of multiple N, P, and K fertilizer combinations on adzuki bean (Vigna angularis) yield in a semi-arid region of northeastern China.

Nitrogen (N), phosphorus (P), and potassium (K) exert various effects on adzuki bean yields. Our research was conducted in a semi-arid area, and four test sites were established in environments that have chernozem or sandy loam soils. During a five-year period, the effects of N, P, and K fertilizers on yield were comprehensively investigated in field trials (2014-2016) and for model-implementation trials (2017-2018), with models established prior to the latter. In the field trials, 23 treatments comprising different N, P, and K combinations significantly affected both yield and yield components, and regression analysis indicated that the experimental results were suitable for model establishment. The model subsequently demonstrated that the yield and the yield components were more sensitive to N and K fertilizer than to P fertilizer. Moreover, the yield and yield components increased. These yield increases were intense in response to the 0.5 to 1.34 levels in terms of the single effects; interaction effects; and the effects of combinations of N, P, and K fertilizers. Moreover, the effects of combinations of N, P, and K fertilizers were more significant on yield than were the single or interaction effects of N, P, and K fertilizers. The optimal fertilizer combination that resulted in high yields (≥1941.53 kg ha-1) comprised 57.23-68.43 kg ha-1 N, 36.04-47.32 kg ha-1 P2O5 and 50.29-61.27 kg ha-1 K2O. The fertilizer combination that resulted in the maximum yield was 62.98 kg ha-1 N, 47.04 kg ha-1 P2O5 and 59.95 kg ha-1 K2O (N:P2O5:K2O = 1:0.75:0.95), which produced the model-expected yield in trials at multiple sites. An economical fertilizer combination was determined on the basis of the best fertilizer measures in consideration of the cost of fertilizer and seed; this combination achieved yields of 2236.17 kg ha-1, the profit was 15,653.16 Yuan ha-1, and the corresponding rates were 57.60 kg ha-1 N, 47.03 kg ha-1 P2O5, and 31.64 kg ha-1 K2O (N:P2O5:K2O = 1:0.82:0.55).

High-throughput novel microsatellite marker of faba bean via next generation sequencing.

BACKGROUND: Faba bean (Vicia faba L.) is an important food legume crop, grown for human consumption globally including in China, Turkey, Egypt and Ethiopia. Although genetic gain has been made through conventional selection and breeding efforts, this could be substantially improved through the application of molecular methods. For this, a set of reliable molecular markers representative of the entire genome is required. RESULTS: A library with 125,559 putative SSR sequences was constructed and characterized for repeat type and length from a mixed genome of 247 spring and winter sown faba bean genotypes using 454 sequencing. A suit of 28,503 primer pair sequences were designed and 150 were randomly selected for validation. Of these, 94 produced reproducible amplicons that were polymorphic among 32 faba bean genotypes selected from diverse geographical locations. The number of alleles per locus ranged from 2 to 8, the expected heterozygocities ranged from 0.0000 to 1.0000, and the observed heterozygosities ranged from 0.0908 to 0.8410. The validation by UPGMA cluster analysis of 32 genotypes based on Nei's genetic distance, showed high quality and effectiveness of those novel SSR markers developed via next generation sequencing technology. CONCLUSIONS: Large scale SSR marker development was successfully achieved using next generation sequencing of the V. faba genome. These novel markers are valuable for constructing genetic linkage maps, future QTL mapping, and marker-assisted trait selection in faba bean breeding efforts.

Development of 161 novel EST-SSR markers from Lathyrus sativus (Fabaceae).

PREMISE OF THE STUDY: Expressed sequence tag (ESTs)-derived microsatellite markers were developed in Lathyrus sativus by screening the National Center for Biotechnology Information (NCBI) database. The usefulness of these novel markers was validated for size polymorphism among grasspea accessions. • METHODS AND RESULTS: Three hundred EST-simple sequence repeat (SSR) primer pairs were identified and loci characterized for size polymorphism among 24 grasspea accessions from worldwide sources. Among them 139 SSR loci produced no PCR product, 117 SSR loci were monomorphic, and 44 SSR loci were polymorphic. The mean number of alleles per locus ranged from two to 11. The observed heterozygosity and expected heterozygosity ranged from 0.000 to 1.000 and 0.042 to 0.836, respectively. • CONCLUSIONS: These novel markers will be useful and convenient to study genetic mapping and molecular breeding in grasspea.

Genetic diversity and relationship of global faba bean (Vicia faba L.) germplasm revealed by ISSR markers.

Genetic diversity and relationships of 802 faba bean (Vicia faba L.) landraces and varieties from different geographical locations of China and abroad were examined using ISSR markers. A total of 212 repeatable amplified bands were generated with 11 ISSR primers, of which 209 were polymorphic. Accessions from North China showed highest genetic diversity, while accessions from central China showed low level of diversity. Chinese spring faba bean germplasm was clearly separated from Chinese winter faba bean, based on principal component analysis and UPGMA clustering analysis. Winter accessions from Zhejiang (East China), Jiangxi (East China), Sichuan (Southwest China) and Guizhou (Southwest China) were quite distinct to that from other provinces in China. Great differentiation between Chinese accessions and those from rest of the world was shown with a UPGMA dendrogram. AMOVA analyses demonstrated large variation and differentiation within and among groups of accessions from China. As a continental geographic group, accessions from Europe were genetically closer to those from North Africa. Based on ISSR data, grouping results of accessions from Asia, Europe and Africa were obviously associated with their geographical origin. The overall results indicated that the genetic relationship of faba bean germplasm was closely associated with their geographical origin and their ecological habit.

The genetic diversity of the Vigna angularis complex in Asia.

A selected set of accessions of components of the azuki bean (Vigna angularis) complex comprising 123 cultivated accessions and 23 wild or weedy accessions from Bhutan, China (including Taiwan), India, Japan, Korea, and Nepal was analyzed using amplified fragment length polymorphism (AFLP) methodology. Using 12 AFLP primer pairs, 580 unambiguous bands were generated, 313 (53.9%) of which were polymorphic among azuki bean accessions. All 580 bands were used to assess phenotypic (band) and genetic (nucleotide) diversity among the 146 azuki bean accessions. The results indicate five major groups of azuki bean germplasm primarily associated with geographic origin of accessions and their status: wild, weedy, or cultivated. These five groups are (i) Himalayan wild, (ii) Nepal-Bhutan cultivated, (iii) Chinese wild, (iv) Taiwan wild - Bhutan cultivated, and (v) northeast Asian accessions. Within the northeast Asian accessions, three subgroups are present. These consist of (v1) Japanese complex - Korean cultivated, (v2) Japanese cultivated, and (v3) Chinese cultivated accessions. The results suggest domestication of azuki bean occurred at least twice, once in the Himalayan region of southern Asia and once in northeast Asia. The remarkable diversity of azuki bean germplasm in the Himalayan region compared with other regions suggests this is a rich source of germplasm for plant breeding. The results suggest there are important gaps in the germplasm collections of azuki bean and its close relatives from various parts of Asia and that specific collecting missions for Vigna germplasm related to azuki bean in the highlands of subtropical Asia are needed.