Green and dry forage yields of alfalfa “Medicago sativa, L.” populations subjected to selection cycles for glyphosate tolerance

Abstract EN

The recent study was an attempt to measure the influence of selection for glyphosate tolerance in alfalfa germplasm on green and dry forage yields.

Two cycles of recurrent selection for Glyphosate tolerance were imposed on each of five base population.

Evaluation of selected cycles (C1 and C2) along with base populations (C0) was carried out for each population as a split plot design with Glyphosate treatment (+ and -) as main plots and populations (C0, C1 and C2) as a sub –plot.

The recorded dry forage yield from the studied population was similar irrespective of glyphosate treatment.

Meanwhile, green, and dry forages of studied population, significantly varied (p≥0.01) in ranke or magnitude depending on selection cycle (significant population × selection cycle interaction).

In addition, green forage yields of glyphosate treatments significantly varied (p≥0.05) among populations and selection cycles (significant glyphosate treatment × population × selection cycle).

The least green forage yield resulted from C.

U.

F.

101population when treated with glyphosate (110.32 ton.

ha-1).

That was not significantly different from green forage yields produced by any of Baladi 1and Siwa populations under glyphosate treatment.

The highest significant green forage yields were obtained from any of Siriver or Baladi 1 population without glyphosate treatment (194.12 and 142.77 tons.

ha-1 for the former and the latter, respectively).

On another words, the most sensitive population to glyphosate treatment in terms of green forage yield was Baladi 1, since, it produced the least green forage yield with glyphosate application (110.91 tons.

ha-1) versus significantly the highest green forage yield without glyphosate application (192.77 tons.

ha-1).

The least green forage yield resulted from C.

U.

F.

101population when treated with glyphosate (110.32 ton.

ha-1).

That was not significantly different from green forage yields produced by any of Baladi 1and Siwa populations under glyphosate treatment.

Response of dry forage yield to population × selection cycles interaction took similar pattern to what noticed in green forage yield.

C.

U.

F.

101 showed a significant reduction of 10.26% in dry forage yield of cycle two relative to cycle one.

While, Hasawi population, recorded a significant increase in dry forage yield of 15.52% with the second cycle of selection relative to cycle one.

Siwa population, showed lowering in dry forage yield with one cycle of selection for glyphosate tolerance (-7.373% ) and an increase of 6.998% at second cycle of selection relative to cycle one.