Drought effects on yield and its components in Indian mustard (Brassica juncea L.)

Abstract

Effects of drought on yield and yield components were investigated during the spring season 2000-2001 by growing 14 Indian mustard genotypes under irrigated and rain-fed conditions at Bharatpur and Jobner. A disease and pest management schedule was followed when required. The drought susceptibility index (DSI) for seed yield and component characteristics was calculated to characterize the relative tolerance of genotypes. Plant height, primary branches, secondary branches per plant, 1000-seed weight and seed yield were reduced under rain-fed conditions. The top five genotypes at Bharatpur that showed tolerance to moisture stress for seed yield, as indicated by their lowest DSI, were, in descending order PSR-20, PRO-97024, JMMWR-941, IS-1787 and PCR-7, whereas at Jobner these were JMMWR-941, RC-1446, PSR-20, RH-819 and ÔVarunaÕ. Of these, PSR-20 and JMMWR-941 were among the top six at both locations. These genotypes also showed relatively low DSI for one or more characteristics, such as primary branches per plant, secondary branches per plant, harvest index and seed : husk ratio. Genotypes with the lowest DSI, particularly for seed yield at both locations, would serve as useful donors in the breeding programme for improving the drought tolerance of existing Indian mustard cultivars.Key words: Brassica juncea -drought -susceptibility index -seed yield -oil content Rapeseed-mustard crops in India account for about 21.6% and 23.2% of the total oilseed harvested area and production, respectively (Anonymous 2004). Indian mustard is predominantly grown on nearly 90% of the total harvested area, covering up to 7.0 m ha. Nearly 37% of the total rapeseedmustard area is rain-fed, where the crop is severely affected by drought, resulting in acute yield losses particularly in the drought-prone areas of Eastern and Western India which are populated largely by resource poor farmers with small land holdings. The effect of drought depends on the time of its occurrence, duration and intensity. Mustard genotypes with drought tolerance trait(s) yielded better than those without such trait(s) under water stress conditions (Singh et al. 1988). Therefore, investigating the effects of drought on yield and yield components in Indian mustard is very important for identifying drought-tolerant traits that can be incorporated into high-yielding varieties. This study is aimed at investigating the effects of drought on a wide range of genotypes of Indian mustard and identifying suitable selection criteria for drought tolerance. Materials and MethodsPlant material and experimental locations: Fourteen genotypes of Indian mustard, Brassica juncea L. (IS-1787, BE-3121, RC-53, PRO-97024, RC-1446, DIR-673, RC-5, EC-347852, JMMWR-941, PSR-20, ÔVarunaÕ, PCR-7, RN-393 and RH-819) were grown during the spring season (October-April) of 2000-2001 at two locations in Rajasthan (India), Bharatpur and Jobner, which are approximately 230 km apart.The rainfall during the cropping season, October-April, was 0.5 and 0.9 mm at both locations, respectively, as this...

Assessment of Variability for Drought Tolerance Indices in Some Wheat ( Triticum aestivum L.) Genotypes

“…Because of they revealed minor yield reductions under drought condition. These results are in harmony with Chauhan et al (2007) and Kumar et al (2014). However, the development of different genotypes in relation to time of drought stress or shortage of adjustment with difficult conditions might due to the reason of variation in SSI.…”

Evaluation of and selection criteria for drought resistance in Chinese semiwinter rapeseed varieties at different developmental stages

“…In addition to seed yield, drought stress also caused 20-40% reductions in SW, NPP, HFB and PH and <16% reductions in NPB, NSP and DM in the present study ( Table 2). Some of these results, however, conflict with a report in B. juncea, which found that SW was only marginally (5.3-6.0%) reduced under rain-fed conditions (Chauhan et al 2007). One explanation for the reduction in the values of agronomic characteristics for Brassica crops under rain-fed conditions is that the plants experienced decreased translocation of assimilates and growth substances, impairing nitrogen metabolism, inducing a loss of turgidity and, consequently, reducing sink size (Henry andMcDonald 1978, Kumawat et al 1997).…”

“…The occurrence, duration and intensity of drought have profound impacts on rapeseed growth and production (Deepak and Wattal , Chauhan et al. ). Relative to non‐drought conditions, drought is associated with a significant loss of crop yield, shorter plant height, reduced oil content, fewer primary branches, lower 1000‐seed weight, fewer pods per plant and fewer seeds per pod but an increase in protein content (Maliwal et al.…”

Genome-wide association mapping for grain yield components and root traits in Brassica juncea (L.) Czern & Coss.

“…4 Location of associated markers for individual traits, identified by association mapping approach on the 18 chromosomes of B. juncea. Plheight plant height, secybranches number of secondary branches, rootdia root diameter A stress during any of these conditions tends to depress plant height and branch number and consequently the crop productivity due to a reduced number of pods/plant, premature flower fall and reduced seed number per pod (Chauhan et al 2007;Hosseini and Hassibi 2011). Studies have also shown that yield component compensation is an expected outcome of several inter-related traits sharing a common metabolic pool; nevertheless, there are reports of significant positive correlation between grain yield with secondary branches, plant height and seed size (Singh and Chowdhury 1983).…”