Abstract Detail

Genetics Section

Ahmed Wahocho, Dr. Niaz [1].

Characterization of natural variation of shoot and root growth in response to nitrogen availability in Brassica rapa L.

Nitrogen (N) is one of the most important nutrients for plant growth and development. Improving nitrogen use efficiency (NUE) especially at low input is essential for sustainability of crop production. Brassica rapa comprises important crops used as vegetables, oilseed and fodder grown worldwide. The objective of this study was to assess the genetic variation in shoot and root growth under low nitrogen (LN) and high nitrogen (HN) conditions in B. rapa. In total, 45 accessions were screened for their shoot and root growth characters in hydroponic culture. The accessions differed significantly in the extent of growth reduction under N limiting conditions. Wide genetic variation was observed for the shoot and root traits under both N conditions. Both tolerant and sensitive accessions to LN condition were identified. On average, the shoot dry biomass of the 45 accessions grown under LN was reduced by 32 % compared to HN. The greatest reduction 39.53 % was recorded in cultivar group Chinese cabbage (Sep. Pekinensis), closely followed by a cultivar group of yellow Sarson (Sep. Tricolaris) where 35 % reduction in shoot dry biomass was recorded. However, some accessions belong to Pak Choi, Chinese cabbage and turnip were almost unaffected regardless of N nutrition used. Accessions also showed highly variable response to root traits under both N conditions. In most accessions, root traits, including root dry biomass, root thickness increased at HN condition. In contrast primary root length decreased under the same condition. However, the total root length was almost unaffected by N nutrition, whereas the range of variations existed among accessions. The present results will facilitate the choice of B. rapa accessions for further genetic analysis of quantitative traits related to nitrogen use efficiency.
Key Words: Natural variation, Shoot and root growth, nitrogen, Brassica rapa

1 - Sindh Agriculture University TandoJam, Pakistan, Horticulture, Department of Horticulture SAU TandoJam, 70060, Pakistan, TandoJam, Sindh, 70060, Pakistan

Keywords:
natural variation
root growth
nitrogen
Brassica rapa
Shoot growth.

Presentation Type: Oral Paper:Papers for Sections
Session: 6
Location: Salon 15/16/The Shaw Conference Centre
Date: Monday, July 27th, 2015
Time: 9:15 AM
Number: 6006
Abstract ID:446
Candidate for Awards:None