Characterization and Mapping of retr04, retr05 and retr06 Broad-Spectrum Resistances to Turnip Mosaic Virus in Brassica juncea, and the Development of Robust Methods for Utilizing Recalcitrant Genotyping Data

Turnip mosaic virus (TuMV) induces disease in susceptible hosts, notably impacting cultivation of important crop species of the Brassica genus. Few effective plant viral disease management strategies exist with the majority of current approaches aiming to mitigate the virus indirectly through control of aphid vector species. Multiple sources of genetic resistance to TuMV have been identified previously, although the majority are strain-specific and have not been exploited commercially. Here, two Brassica juncea lines (TWBJ14 and TWBJ20) with resistance against important TuMV isolates (UK 1, vVIR24, CDN 1, and GBR 6) representing the most prevalent pathotypes of TuMV (1, 3, 4, and 4, respectively) and known to overcome other sources of resistance, have been identified and characterized. Genetic inheritance of both resistances was determined to be based on a recessive two-gene model. Using both single nucleotide polymorphism (SNP) array and genotyping by sequencing (GBS) methods, quantitative trait loci (QTL) analyses were performed using first backcross (BC1) genetic mapping populations segregating for TuMV resistance. Pairs of statistically significant TuMV resistance-associated QTLs with additive interactive effects were identified on chromosomes A03 and A06 for both TWBJ14 and TWBJ20 material. Complementation testing between these B. juncea lines indicated that one resistance-linked locus was shared. Following established resistance gene nomenclature for recessive TuMV resistance genes, these new resistance-associated loci have been termed retr04 (chromosome A06, TWBJ14, and TWBJ20), retr05 (A03, TWBJ14), and retr06 (A03, TWBJ20). Genotyping by sequencing data investigated in parallel to robust SNP array data was highly suboptimal, with informative data not established for key BC1 parental samples. This necessitated careful consideration and the development of new methods for processing compromised data. Using reductive screening of potential markers according to allelic variation and the recombination observed across BC1 samples genotyped, compromised GBS data was rendered functional with near-equivalent QTL outputs to the SNP array data. The reductive screening strategy employed here offers an alternative to methods relying upon imputation or artificial correction of genotypic data and may prove effective for similar biparental QTL mapping studies.

Control of Apple Replant Disease Using Mixed Cropping with Brassica juncea or Allium fistulosum

Evidence indicates that Allium and Brassica species which release bioactive compounds are widely used in bio-fumigation to suppress soil-borne diseases. However, the active molecules of such plant residues are easily volatilized. In this study, we conducted mixed cropping of the apple tree with Allium fistulosum or Brassica juncea; the results demonstrated that such mixed cropping significantly improved the growth of the grafted apple seedlings and alleviated apple replant disease (ARD) for two years. The terminal-restriction fragment length polymorphism profile results showed that the soil fungal community demonstrated distinct variation and diversity in terms of composition. A. fistulosum and B. juncea significantly improved the Margalef, Pielou, and Shannon indices. In addition, the analyses of clone libraries showed that A. fistulosum and B. juncea promoted the proliferation of antagonistic fungi such as Mortierella, Trichoderma, and Penicillium, and inhibited the proliferation of pathogens such as Fusarium. Fusarium. Proliferatum (F. proliferatum) was abundant in replanted soil and proved to be an aggressive pathogen of apple seedlings. Our findings thus indicate that apple tree mixed cropping with A. fistulosum and B. juncea was an effective long-term method for modifying the resident fungal community and alleviating ARD.

The elemental defense effect of cadmium on Alternaria brassicicola in Brassica juncea

Background The elemental defense hypothesis states a new defensive strategy that hyperaccumulators defense against herbivores or pathogens attacks by accumulating heavy metals. Brassica juncea has an excellent ability of cadmium (Cd) accumulation. However, the elemental defense effect and its regulation mechanism in B. juncea remain unclear. Results In this study, we profiled the elemental defense effect and the molecular regulatory mechanism in Cd-accumulated B. juncea after Alternaria brassicicola infection. B. juncea treated with 180 mg Kg− 1 DW CdCl2 2.5H2O exhibited obvious elemental defense effect after 72 h of infection with A. brassicicola. The expression of some defense-related genes including BjNPR1, BjPR12, BjPR2, and stress-related miRNAs (miR156, miR397, miR398a, miR398b/c, miR408, miR395a, miR395b, miR396a, and miR396b) were remarkably elevated during elemental defense in B. juncea. Conclusions The results indicate that Cd-accumulated B. juncea may defend against pathogens by coordinating salicylic acid (SA) and jasmonic acid (JA) mediated systemic acquired resistance (SAR) and elemental defense in a synergistic joint effect. Furthermore, the expression of miRNAs related to heavy metal stress response and disease resistance may regulate the balance between pathogen defense and heavy metal stress-responsive in B. juncea. The findings provide experimental evidence for the elemental defense hypothesis in plants from the perspectives of phytohormones, defense-related genes, and miRNAs.

Consumptive use pattern of mustard (Brassica Juncea L) under different soil and climatic environments

Mustard is an important cash crop in north India where it is widely grown under different climatic environment and soil types. In the present study, evapotranspiration and other agro-meteoralogical data for four agroclimatic locations, viz., Jorhat, Samakhunta, Raipur and Jodhpur have been utilized to understand consumptive use and related aspects of mustard. The evapotranspiration values recorded by lysimeters, global radiation and actual soil moisture data of Jorhat and the computed soil moisture have been used. The study suggests that the nlustard plant uses n10re water at all the stations except at humid location where consumptive use is least. The utilization is n1aximum betw~n 31-60 days after sowing in case ofJorhat l;er 111 and Samakhunta. The con1puted soil 1110isture estimates for 45 cm layer agree with the actual soil moisture. 15-1 The analysis also brings oUt that during the seventh week after sowing, the ratio of consumpiive use and rti. Ru Ilobal radiation attains a nlaxin1um value. This infonnation can be used for detennining irrigation needs and ular m computing energy balance components in the crop. ncymodsE..C.1..S.l.R...llC

Effect of light-converting coatings on the growth of Sarepta mustard (Brassica juncea L.) plants colonized by associative microorganisms

The effect of colonization by beneficial associative microorganisms Pseudomonas putida KT 2442 and Rhodococcus erythropolis X5 on the growth of Sarepta mustard (Brassica juncea L.) under a covering light-converting material containing organic photoluminophore, in vitro and in vivo, was investigated. The combined use of microbial colonization and photoluminophore coating led to stimulation of plant growth much stronger (2.4 times more) than separately only photoluminophoric coating (1.3 times) or colonization (2.1 times). These data indicate that when covering materials with photoluminophores are used in agrobiotechnologies, luminescent red light (610-730 nm) induces an increase in biochemical processes not only in plants, but also in microorganisms that supply plants with growth regulators and other useful metabolites. The data obtained are relevant for further study of the photobiological mechanisms of interactions between the plant-microorganism system in agrobiotechnologies.

Pengaruh Pupuk Hayati terhadap Pertumbuhan Tanaman Sawi (Brassica juncea L.) di Kampung Sidomulyo, Distrik Oransbari, Kabupaten Manokawari Selatan, Provinsi Papua Barat

Tanaman sawi hijau (Brassica juncea L.) merupakan salah satu komoditas hortikultura sayuran daun yang banyak digemari oleh masyarakat karena rasanya enak, mudah didapat, dan budidayanya juga tidak terlalu sulit. Produksi sawi dapat ditingkatkan melalui budidaya yang baik, yaitu pemeliharaan dan pemupukan yang tepat. Pemupukan dengan menggunakan pupuk hayati sangat baik untuk pertumbuhan sawi dengan kualitas yang baik dan dapat meningkatkan produksi sawi caisim. Penelitian ini bertujuan untuk mengetahui pengaruh pupuk hayati di Kampung Andai Distrik Manokwari Timur Kabupaten Manokwari Provinsi Papua Barat dan efektivitas penyuluhan serta pengaruh faktor karakteristik petani terhadap perubahan pengetahuan petani di Kampung Sidomulyo, Distrik Oransbari, Kabupaten Manokwari Selatan, Provinsi Papua Barat. Metode kajian yang digunakan adalah Rancangan Acak Kelompok (RAK), dengan menggunakan 3 perlakuan dan 6 ulangan. Perlakuan diuji pada tanaman sawi, variabel yang diukur meliputi luas daun, jumlah daun, tinggi tanaman dan berat segar tanaman. Pelaksanaan penyuluhan diikuti oleh 20 responden dengan materi penyuluhan tentang penggunaan pupuk organik hayati menggunakan metode ceramah, diskusi dan demonstrasi cara. Jumlah skor pada tes awal sebesar 790 point, dengan rata-rata 39,50 point berada pada kriteria cukup. Jumlah skor pada tes akhir sebesar 1.110 point, dengan rata-rata 55,50 point berada pada kriteria sangat baik. Kesimpulan dari penelitian ini yaitu Perlakuan pupuk organik hayati dengan dosis 50 cc/10 liter berpengaruh terhadap luas daun, jumlah daun, tinggi tanaman dan berat bersih tanaman sawi (Brassica juncea L.) bila dibandingkan dengan perlakuan kontrol dan pupuk urea. Faktor umur, Tingkat pendidikan dan lama bertani secara bersama-sama (simultan) berpengaruh terhadap perubahan pengetahuan petani dan sasaran penyuluhan namun secara persial tingkat pendididikan dan lama bertani benar-benar berpengaruh secara signifikan terhadap perubahan petani sasaran penyuluhan.